"Blind" and "Deaf" Thoughts in Leibniz and Cartesianism


   Leibniz used the expression "Cogitationes caecae" or "Cognitio caeca" in some of his Latin works to indicate a kind of thinking that, although it is efficient from  the cognitive viewpoint, it does not allow a discerning vision of its meaning. Leibniz refers, then, to such expressions when, both in Nouveaux Essais and in Essais de Teodicée, he dwells on the limits of this kind of thinking under an ethic-psychological profile.
   He writes that this French expression has the same meaning of the Latin expression "Cogitationes caecae", but he adds that "Pensées sourdes" are not able to touch the soul and modify our way of feeling and behaviour.
The expression "Pensées sourdes", already used in particular by F. Lamy, indicates, in the field of Cartesianism, a kind of "marginal" and "clandestine" thinking which develops collaterally towards the conscience at a preconscient or inconscient level.
  The following essay wants to clarify the relationship between Leibniz’s two expressions according to the different meanings that the second one assumes, respectively, in Leibniz's works and within Cartesianism.


“Blind” and “Deaf” Thoughts in Leibniz and Cartesianism

   In essays about transparency of thinking, about perceptions of which one is not conscious, about thoughts that guide us during life without realising and in general on relationships between conscious thinking and that which, for various reasons, cannot be considered such, a debate develops within Cartesianism which sees as its principle protagonists A. Arnauld, P. Nicole, and F. Lamy, but which involves, even if indirectly, other philosophers and theologians as well, among whom Malebranche, Poiret, La Forge and Regis.
   The point of reference of such a debate consists of two distinct, but connected, definitions provided by Descartes. According to the first the ego is a “thinking thing”, or “a thing that doubts, that conceives, that asserts, that denies, that desires, that does not desire, that imagines too, and feels” (1): from this definition so one can deduce that however it is thinking in essence, the ego (or the mind) can never stop thinking because the essential peculiarities are never separate from their subject(2). The second definition, integrating the first, considers thinking to be always auto conscious, and attributes to the continual presence of the conscience the origin of transparency which distinguishes it (3). The reciprocal essentiality between thinking and conscience allows, thus, Descartes to deduce from the psychological certainty to think that ontological is a thing that thinks, a deduction that, if thought were not accompanied by the conscience would not be possible, because to think unwittingly does not lead to any certainty to think.
   It is just for the basic function that the “Cogito” has in the area of Cartesianism, that the followers of Descartes consider the identification of thinking and conscience as a presupposed theory, which  being questioned can radically distance itself from the perspective of that philosophy which feeds their speculation. Even those who do not completely agree such identification, certainly cannot do without thoroughly considering and suggesting with caution ones own reserve, because to the  outcome of them are tied the solutions to controversial theological and moral matters. The same Descartes was repeatedly urged by the criticism of opponents or admirers to raise a doubt (or at least to limit) about the validity of these presuppositions (4) that, however, are questioned only when the philosophers above mentioned are in dispute about the unconscious spiritual phenomenon.
   In such disputes, while Arnauld results as a punctual defender of the foundations of Cartesianism, Nicole and Lamy, who are more liberal in their precise reference to the philosophy of Descartes, contest the validity of the identification of thought and conscience, speaking clearly of “thinking about which one does not think” (5). They feed, then, such debates introducing notions like those of “unperceivable thinking”, “secondary thinking”, “marginal”, “clandestine” and “deaf”, notions that imply that all, even in different ways, have a relative absence of conscience.
   The narrow relationship between these kinds of thinking and that what G. Rodis-Lewis calls “the problem of unconscious” (6) - a term which is not in any case to be intended in its contemporary acceptance, but broadly speaking and nearer to that which today we intend with the terms subconscious and preconscious - continues to exist in Leibniz, in whose works “the unperceivable inclinations”, or “small perceptions” have a first hand importance.
   The destiny of the expression “deaf thoughts”, often used by F. Lamy, is different from that used by Leibniz with a new and original meaning, in which the relationship with “the unconscious”, a long way from being clear and taken for granted, instead result vague, and from the first view almost inexistent. While in fact for Nicole and Lamy the “deaf thoughts”, or “clandestine ones”, are like “annoying guests hidden in the depth of the soul”, from where, even if revealing now and again and working on our conscious determination from far away, “make our motives ably play on our behaviour (7), for Leibniz such thinking is apperceived and explicitly formed through characters or  words.
   The expression “deaf thoughts” (pensées sourdes) appears for the first time in the writings of Leibniz in a letter to Princess Sophia in May 1697, in which he states that he doubts whether one can understand the thought without referring to its extension. “In fact I agree - he writes- that there is thinking to which neither the spirit, nor images, nor figures correspond and some of this thinking is distinct. But I do not agree with all the examples presented by the Cartesians because the figure of a thousand angles here designed is not extended more distinctly than some large numbers: it is   a deaf thought, like in algebra, where one thinks in symbols in place of objects. So, often, to abbreviate, words are used thinking of them without analysing them, because that is not necessary in such circumstances”(8).
   It would be enough now to compare this extract from Princess Sophia’s letter with other extracts  from the writings of Leibniz in which he refers to the example of a polygon of a thousand sides, so as to understand  that the French expression “pensées sourdes” is only the translation of the Latin expression “cogitationes caecae”, as Leibniz himself notes explicitly in the only passage of Nouveaux Essais in which he quotes the latter. It appears for the first time in De arte combinatoria, where indicates thinking that is not capable of understanding with a clear vision its own object (9).
  Also in this text he uses the example, Cartesian, of the polygon of a thousand sides or kilyagon: in fact this figure, even if it is distinctly thinkable and definable, does not result as imaginable as much as analytical and clear; so that such a notion does not correspond in our minds with any image able to express a logical picture provided by its definition.
   Other than those brief works in which Leibniz takes up the notion again of  “blind thought”, to develop the mathematical-linguistic aspects (10), it reappears in the important essays about gnosiological  argument “Meditationes de cognitione, veritate et ideis”, of 1684, where its meaning is described in a more articulate way and the kind of knowledge that distinguishes it is set out by Leibniz almost at the top of the graduation which he outlines from the variety of knowledge (11). From these texts “the blind or symbolic thought” results as definable as that which, progressing by signs or characters, avoids going back each time to the idea of things and that, if eventually we are able to construct a suitable “Universal Characteristic”, it would permit us to reason justly as well, transforming automatically in a mathematical error every paralogism of our arguments in natural language. On the other hand, if such thinking can make our reasoning more agile and sure, in any case it is not able, for mechanical and passive use of the signs it involves, to identify the contradictions that are concealed in certain concepts, like, for example, that of “faster motion” (12), or in certain series of thinking. Further, unless the language which is used does not determine its distinction and coherence, it is impossible from such thinking to cancel the confusions caused by the use of approximate meaning and ambiguous words.
    Although being considered by Leibniz the type of more frequent thinking, because it characterizes every kind of calculation (algebra, geometry, or logic combined), as well as the reflections of mankind on different arguments when words are used without worrying to explain their sense, there is no mention in his writings to develop the ethic-psychological order of such a notion. These emerge only when the Latin adjective “caecus” will be substituted by “sourd” in the French works: that is, it seems, the only plausible explanation of the fact that the tightly correlation between the two expressions, “cogitationes caecae” and “pensées sourdes”, has not been noted and/or highlighted by scholars of Leibniz until a short while ago (13).
   The problematic ethic-psychological in which the expression “pensées sourdes” is introduced in the Nouveaux Essays is centred around the relationships between intellect and will. In the XVII century such relationships had already found a syncretic formulation in the quote of a famous Ovidian verse: “Video meliora proboque, deteriora sequor” (14), which, among others, Spinoza, too, used in his “Ethics” to introduce the study of relationships between reason and passion (15). Leibniz, as well, quotes in Nouveaux Essais this verse to summarise the difficulty that reason meets in stemming or modifying the passions, through Filalete, the Lockian character, who uses it to illustrate the typical situation of a man who, addicted to drink, even if distinctly understanding all the negative aspects of such a vice is not able to give it up.
   The contradictory impasse that the Ovidian verse brings to light must not however constitute, according to Teofilo, the Leibnizian character in Nouveaux Essais, a moral alibi, making us believe that we have to abandon all those antique axioms for which “the will follows the major goodness or escapes the major evil felt”. The origin of the scarce solicitation towards the true goodness derives mostly from the fact that in objects or in circumstances in which the senses do not function, our thoughts are, just to say, deaf (in Latin I call them “cogitationes caecas ”) - Leibniz writes - without, that is, perception or sentiment, firm in the pure and simple employment of characters, like that which happens to those who, in algebraic calculation do not consider, now and again, the geometric figure that they represent, given that the word has the same effect on characters of arithmetic and algebra. Often one reasons almost without having the object in the spirit. Now, a knowledge as such is not efficient; to move it one needs something alive” (16).
   This arrangement in a new moral environment as regards that which is collected in the notion of “blind thought”, like an explanatory knot, reveals, so, a new limit of general definable thinking as a symbol as well, that which is not able, “touching the soul”, to provoke choices and behaviour ethically rational. To such inability the Essays de Teodicée also make a reference in the only passage in which Leibniz uses the expression “pensées sourdes” to give an explanation of the resistance of the soul to truth which it knows and denounces, resistance which is more just when “the intellect proceeds most of the time with deaf thoughts”: (17) these, in fact are “little able to touch” (18) and demonstrate the precariousness of the ties between judgement of reason and will (19). When men think of God, of Virtue and Happiness, often “they speak and reason without explicit ideas: these are in their spirit, but they do not bother to deepen the analysis. Sometimes they have the idea of an absent goodness or evil, but very weak (….) so, if we prefer the worse things it is because we feel the goodness and not the evil that they contain, while we do not feel the goodness which is an opposite side. We suppose or believe, or rather simply repeat having faith in others and relying on the memory of past reflections, which the best parts are on the better side and the worst parts on the opposite side. But when we do not overlook them - continues Leibniz - the thoughts and reasoning are a type of “psittacism” that do not offer anything new to the spirit and if we do not take measures to avoid this the wind will carry them away”(20).
   Repeating our reasoning lazily and mechanically, “uti psiptacus” (21), the soul is in fact not affected and the will not shaken, “so there is no need to wonder if in the fight between the flesh and the spirit, the spirit so often gives up”(22); “this fight is no other than the opposition of the different tendencies that make themselves felt often so clearly, while the distinct thoughts are ordinary clear only in power: they could be if they wanted to make the effort to penetrate the sense of the words and characters, but by not doing it, either for negligence or for not enough time, we debate empty words and weak images to lively sentiments” (23).
   The analysis of the meaning of words, making us know that what is implied, seems on the contrary to be able, according to Leibniz, to make us see what are the consequences of our choices as well, consenting us to perceive good or bad that can follow and implicitly pushing us to choose the best solutions. Instead, when the words are used in a repetitive way or in a “blind” one, and we cannot see all that their meaning implies, they continue to prevail in us those inclinations and sensations which, even if perceived only in confusion, shock us in a more vivid way. So, the thought that, from the point of view of a theory of knowledge, is blind, for its inability to identify the contradictions that are hidden in certain concepts or to consider clearly the implications of their meaning inside a complex reasoning (24), is, in a moral  perspective, deaf, in subjective and objective sense of “surdus” in Latin, or deaf as it is not able either to make itself feel or listen.
   In fact, it is possible to distinguish two different orders of causes of deafness of our thoughts. The first one can be considered objective, as it is dependent by arbitrariness of signs we use in respect to their meanings and for the fact that while we think, to proceed in our reasoning, we are obliged to omit analysis. The second one we can consider subjective, because we are responsible ourselves for it, who, even when we could and should deepen the analysis of the meaning of symbols, we limit ourselves to lazily repeating the succession, giving up considering “the ideas”, “the perceptions” and “the sentiments” that such symbols are able to evoke. If from one side, in fact, the relationship between the relative conventionality of signs and the symbolism of thought determines the possible passive and repetitive use of the words, that does not impede the formulation of correct reasoning, neither to be aware of their correctness, given that we can always remember to have controlled them in other circumstances and given that their sense can seem pre-semantically evident to us.
   But when the finality of our reflections is not only cognitive and one wishes on the contrary to motivate or modify moral choices, then the negligence in paying attention to the sense of words that make up our thoughts constitutes the authentic and eliminable reason of their persuasive inefficiency.
   So, if in a certain sense the thoughts themselves do not allow the soul to listen for arbitrariness of the signs in which they are composed in respect to the perceptions or sentiments that they can evoke, in an opposite sense it is the reason itself to conceal behind its own deafness and psychagogic inefficiency when, even being taken up with the most secret passions or desires, continues trusting in the auto-combinatorial capacity of symbols, almost as if committed to a mathematical or algebraic calculation.
  We have seen how, according to Leibniz, in this last case such a blind manner to advance reveals itself to be as correct as necessary, “because the reasoning can be in some way automated  and reduced to the simple manipulation of signs” (25), and because the evocation of ideas corresponding does not result essential for the thought when it is considered as a calculation.
   Nevertheless, it is just this reduction of thinking to calculation that can render opaque the sense of our words and empty of perceptions and sentiments  our thoughts. If then with the notion of “blind thought” Leibniz wants to bring to the light the positive aspects of a reduction of thought to “calculating thought” (rechnendes Denken), this does not imply, as sustains Martin Heidegger (26), that Leibniz considered such a dimension of thought bereft of gaps, so as to be considered the first  promoter  aware of such a reduction. On the contrary, with the notion of “deaf thought” - a notion that in respect of the first is synonymic and at the same time speculating – Leibniz distinctly shows the limits of that reduction which, again according to Heidegger, constitutes one of the metaphysical nucleus of modern thinking.
   The deaf thoughts, not convincing us to follow the best actions and leaving us at the mercy of passions, allow, according to Leibniz, only an imperfect knowledge (27): “they cannot in fact win the concealed disbelief that reigns in the souls of mankind” (28) neither to control that  “uneasiness” or “desire” (29) which is the principle source of their ingeniousness and activity, but reveals a predisposition to pain if, thinking with images “fleeting or vain”(30), mankind does not believe in its thoughts and does not know how to be touched by them (31). In this case the intellect cannot mediate and cannot transform the “unknown inclinations” caused by uneasiness and so contains “an imperfection or impotence”, because words without a real explanation are used (32).
   In any case, as we have seen, the omission of a proper explanation of terms we use in a reasoning is, according to Leibniz, inevitable whenever one wishes to arrive at the conclusion with a fluency and skill necessary. In fact, as “we think a lot of things at the same time, if we cared about each one we should do so at the same time and with the same attention to all”, because we feel that “all make an impression on our senses” (33). Then, as well, “something of our thoughts always remain and nothing can be completely cancelled” (34), we should also think now of all that we have already thought. But it is not possible “to always reflect explicitly on all our thoughts, otherwise the spirit would make a reflection into infinity without ever being able to pass over to a new thought” (35).
   So, for example, “appercepting a present thought, I should always think that I think it and then think that I’m thinking of thinking it and so on until infinity. Instead it is necessary to stop reflecting on all these reflections and that there is at last a thought that allows it to pass without thinking about it. Otherwise we would remain always blocked on the same thing” (36), that would constitute the absurd consequence of considering the apperception as essential to the thought, which, not being able, according to this theory, separate itself from its object, would be obliged to reproduce itself indefinitely in a reflection about itself.
   But just that which constituted for Descartes an effect of co-essentiality of the ego and of the thought, that is, the continuity of the latter, for Leibniz it seems to put in question the other presupposition although fundamental of Cartesian philosophy, constituted from the identification of thought and conscience. Postulating such identification, one arrives according to Leibniz to the paradoxical impossibility of separating any thought from a chain of reflections in which it would reproduce itself until infinity like the object of a repeatable awareness of conscience.
    Every reflection would be destined to monotonously transform every statement in a new enunciation which would include as object through the addition of a “I think” in the place of the subject: in fact, if to think implied thinking of thinking, the mechanism of the apperception would provoke the progressive inclusion of every thought apperceived in a new enunciation of the reflection, inducing us to think univocally of thinking to think it, until infinity. Being that such absurdity is deduced directly from the superimposition of the Cartesian postulates of the continuity of thought and identification of thought and conscience, such absurdity induces Leibniz, who has always declared  to be in agreement with the first one, to accept, as presupposition of his philosophy, the negation of the second one. But from the negation of this - in other words, because thinking does not imply for Leibniz to be conscious of thinking - and from the maintenance of the first  postulate – that is as we always think - it necessarily results that some thoughts of which we have are unconscious.
    In this way, he leads, merely in a logical way, to a conclusion which is apparently the same  attained by Nicole and Lamy. According to them, in fact, the existence of “thoughts of which one does not think” was evident at least as the existence of those meanings “accessories” of words which are destined to remain in the shade, given that every single syntactic collocation in which the words are used is not able to render their meaning explicit and aware. But the deaf thoughts for Leibniz are not like that in respect to a conscience conceived like a clear apperception of an interior impression, that is not because they are indistinct or only confusedly perceived. On the contrary, they are deaf because they are incapable of arriving at the bottom of the soul, where  moving and opposing all the desires of “uneasiness”, there are too those thoughts which the opaqueness of the symbols and of the words not only does not consent to re-find them, but weaves and let understood besides the activity of apperception.
   The origin of the awareness of many thoughts seems in fact to be owed to the necessity to let the words follow and combine without an explanation of their meaning and without attention to “images” or to “sentiments” which they are able to evoke. From this point of view thinking deafly implies the “leave to pass” also those thoughts which would explain the sense of the notions that we nominate in our reasoning, “leave to pass” which is equal to that same omission of analysis that reduces to mere characters or names even the words from natural language with which we formulate our moral intentions.
   So, searching to gather ties between that which Leibniz calls “deaf thoughts” and their relation to the unperceivable activity of the spirit, still less, in consequence, to the sense of expression as Lamy says, it is inevitable to place the accent on different concepts of the unconscious which it consents to individualize in the two authors. In Leibniz they are not in fact the deaf thoughts themselves to be unaware, or “obscure and clandestine”, but they pre-suppose the existence of other thoughts which, not being formed, are obliged to stay at least for the moment not thought. As such not being evoked from words, such thoughts not perceived witness the incompleteness of our attention to their semantic determination, incompleteness that can reduce them to entities merely combined, or equivalent to arithmetical or algebraical signs. Like these, in fact, the words, when used deafly, follow and combine in sentences, leaving trapped in their sense the essential contents towards the total of the same, but leaving “to pass”, on the contrary, all the others which could throw a new light on the psychological determination of  their combinations. Just for this effect “marginal”, “accessories” or “connotative” of the sense of the words they seem to assume, in a Leibnizian viewpoint, the existence of a systematic structure beneath every specific combination of words.
   The same requirement advised by Leibniz to render coherent and complete the paradigmatic structure of a “universal language” seems in fact to derive only from the knowledge of a pre-existing one, in respect to every act of “parole”, of a linguistic system that consents to interpret every thought expressed as the topical presentation of possibility implicit in such a system itself, beyond which continues in any case, insisting on all the others that it includes as its own analytical or “connotative” developments.
   In today’s terms, the permanence in the thought of a “langue” in respect of every other act of  “parole”, is that can allow at every step of reasoning to unravel it in its semantic contents and to increase it in directions that are not suspicious not considering such decomposition. It is in fact the case of the notions of “faster motion”, which, according  to Leibniz, hides behind its distinct  conceivability its own auto contradictory implications.
   In any case, every analytic decomposition of terms, like every passage from the explicit to implicit, is also that which guarantees for Leibniz an enlarged connotation of the sense of every sentence and, at the same time, is capable of producing an increase of its psychological resonance.
   The deaf thoughts of which he speaks, in this sense, not only result an inconsistent defence against the most obscure solicitations of the soul, but are in their turn producers of other possible thoughts and not thought at the moment. What in fact does not become  linguistically formed in the interior of a reasoning, seems to be destined to remain latent and gives, however, proof of its permanence in the thought leaving to the expressed word only its empty sound or to written characters their “weak and vain images”.
   So, behind the moral prospective that is the background of Leibniz’s writings about the notion of “deaf thoughts” another is hidden, more rightly linguistic, capable of suggesting the supposition more favourable of an elimination or limitation of the deafness of thoughts. This consist, in fact, in encouraging both a more profound analysis of the meaning of the words and to the construction of a “universal language”, whose symbols, enjoying a better transparency in respect of their meanings or their referents, are able to enrich our imagination (37).
   According to Leibniz that should consent, in fact, also more pertinence of moral thoughts to that of internal states which propose to describe and modify, gathering emotional implications through the statements of their semantic implications or suggestions.
   We have seen that “deaf thoughts” of which Lamy speaks know “how to work from far away”: they can in fact also modify, from a distance in time, our state of mind if we bother to listen to the right perceivable effects of the wishes they manifest (38); like the “inclinations” or “non-sensitive dispositions” of which Leibniz speaks, they seem able to renew the conscience, but this happens only when we work to “continue to enter in the depths of the heart, to observe it, to support it, to probe it, to penetrate it” (39), using such an aim, as Lamy suggests in a passage from his De la connaissance de soi meme, of a psychological technique very comparable to that one which is well noted today by free associations (40). Instead, the defect that, in the Leibnizian meaning, denounce the “deaf thoughts” is just that of  not supporting the secret inclinations of the soul, relating them to the same purposes of reason.
   Nevertheless, Leibniz himself recognises that just as the work of a sculptor can be smooth, instead of having obstacles, from the grain of the block of marble on which he is working, because he knows how to manage it, so, if the reason could manage the dispositions of the soul which he proposes to control, his intervention would result of course, less tiring and more efficient. It should make sure that those same inclinations that are for their nature susceptible by opposite destinies, are gathered around “series of thoughts” which one judges the best, transforming like this in habits which would give us virtue “thanked for and almost spontaneous” (41).
   Unfortunately, though the heart has many ways to resist the truth which the spirit knows and denounces (42), at least as many as it still has today “the unconscious” to thwart those interpretations that, even being recognised as correct, are not able to act on the personality of the patient in an analytical treatment. Not by chance Freud seemed to provide such inefficiency, apparently not justified, an explanation the same as that of the notion of “deaf thoughts” provided by Leibnizian psychology. In the work of 1915 Das Unbewubte he notes, in fact, that if “we inform a patient of his removed representation, at first this will not change his psychic   situation at all”: in fact “the removal is not abolished if the conscious representation is not first joined by the unconscious mnestic trace. Only when this last one has become conscious itself  it has gained success…”, and that because “to have heard and to have lived are two completely different things for the psychological nature” (43).
   So, as for Freud it is not sufficient to express removed thoughts to assume to have subtracted them from the unconscious, the same, the “deaf thoughts” of which Leibniz speaks can be considered -  even being apperceived and distinctly comprehensible – unable to join up to psychic traces almost always unperceived and that manifest wishes of uneasiness.
    Between the two meanings of the expression “deaf thoughts” – that of Lamy and that of Leibniz – it is possible to individualize in any case a close correlation. The fact that some thoughts lead to others, which draw conclusions that the previous have not had the way or time to gather, confirms that which both our two authors sustain. In fact, to be able to leave these thoughts “seconds” to flourish , which are defined “marginal”, “clandestine”, or “deaf” by Lamy, it is necessary that the thoughts “first” are concluded and are assumed, as Leibniz sustains, as a new object of an ulterior reflection. These ulterior reflections, however, as Lamy sustains, do not always develop in a conscious way because it is part of a speech which by bits follows unconsciously. So, as Descartes had sustained, we always think, and though, as Leibniz after specified, we cannot be conscious of every one of our thoughts, because otherwise we should always remain blocked in the same repeated reflection, it is necessary that some of our thoughts continue in a “clandestine”, “marginal”, or “deaf” condition, and so at least relatively unconscious, with all the psychological and moral contraindications that such a condition can imply and that the Leibnizian notion of “deaf thoughts” makes evident.
  These, in fact, are conscious only when and as they become apperceived and expressed, not because they are capable of overcoming the resistance that separates the “heart” from the “spirit”, but only when such resistances have been won, the consciousness becomes for Leibniz authentic and complete. Only in this case, in fact, thoughts are able to lead their reasons there where wishes act.
    However, notwithstanding this anticipation of Freud’s thought - and notwithstanding the same influence that Leibniz has exercised, specially through Herbart, on Freud - the discovery brought about from the notion of “deaf thoughts” to the history of  philosophic thinking goes beyond the ethic-psychological perspective to which such notions seem to refer. They seem, in fact, to allude to a structural property of the same human thought, for which every “present” thought, that is considered in the lapse of time in which it is formed and concluded, implies the onset of other thoughts which are destined to remain, at least for the moment, unconscious, and this is not so much for their contents, but for the symbolic effects of different significant chains with which every thought is virtually correlated.
   If the Freudian unconscious is characterised by its content - as shows the fact that Freud,  after some hesitation at first, opted for the term ‘unconscious’ (Umbewubte), rather than ‘subconscious’ (Unterbewubte), just to underline that the content “um-bewubt” oppose those that result acceptable for the conscious orientation of the ego (44)- the notion of “deaf thoughts” seems instead to show like unconscious thoughts are born for reasons that we can define “only symbolic”, and so, in Leibnizian terminology, “blind” (45), because such thoughts are able to develop independently from a reflection knowing their meaning. They constitute a collateral effect of the conscious thought, let alone the sign of a gap in the sense that it manifests. Every thought evokes and suggests, in fact, some developments destined to remain banished, at least for the moment, in a dimension “deaf and clandestine”, except to work in hiding to be able to re-emerge at the level of the conscious and so be able to continue the speech which at every turn, and for structural reasons, is obliged to stay, under other aspects, cut off and unresolved.


Editions of the works by Leibniz  with relative abbreviations.

Leibniz G.W. : Sämtliche Schriften und Briefe, edited by Preussische Akademie (now Deutsche Akademie) der Wissenschaften zu Berlin, Leipzig, 1950 and following (=Ak.)
Leibniz G.W. : Die Philosophischen Schriften,  edited by C.I. Gerhardt, in VII vols., Berlin, 1875-1890 (=Ger. Ph.)
      Leibniz G.W. : Textes inedits d’aprés le manuscrits de la Bibliothéque Provinciale de Hanovre,
   Published and noted  by Gaston Grua, in II vols., Paris, 1948 (= Grua).


1) R. Descartes, Second  Meditation, in Oeuvres, edited by  C. Adam e P. Tannery (= AT), Paris 1897-1913, vol. IX, pages 21-22.
2) A. Arnauld:  «Atqui necessaríum videtur ut mens semper actu cogitet: quia cogitatio constituit eius essentiam»; in AT, vol. V, p. 193.
3) I refer here to transparency that allows the thought to become, in as much as auto-conscious, the immediate object of reflection (see Descartes , AT, vol.  V, p. 149).
      4) Arnauld, being himself interpreter considering others, writes to Descartes that: «cum ea sit natura cogitationis, ut illius semper simus conscii, si semper actu cogitamus, debemus semper esse conscii nos cogitare; at id experientiae repugnare videtur, maxime in somno ». (Arnauld a Descartes, July  1648, AT, vol. V, p. 214 and IV Obiections, AT, vol. VII, p. 264).
5) F. Lamy, De la connaissance de soi même, II edn., Paris, 1701, in VI vols; tome III, p. 375.
Lamy mentions, in this passage, the terms of the problem in question: “There has been lately a wide discussion to know whether there are thoughts about which we don’t think. The only expression at the beginning seems so ridiculous to some authors, that they did not find it difficult to treat it as a joke. But following a deeper reflection on themselves they have considered, in time, these thoughts are not only bearable, but even pleasant (my translation).
6) G. Rodis-Lewis, Le problème de l'inconscient et le cartesianisme, Paris, 1950.
7) F. Lamy, De la connaissance de soi même, quoted edition, t. III, p. 383.
8) G.W. Leibniz, Ger. Ph., vol. VII, p. 555.
9) G.W. Leibniz, De arte combinatoria , Ger. Ph. vol. IV, p. 35.
10) These works, in chronological order are: Commentaliuncula de judice controversarum, in AK., VI R. I B, p. 551;  Demonstratio propositionum primarium, in AK, VI R. II B, p. 481; Accessio ad aritmeticam infinitorum , in AK,  II R. I B, p. 228.
11) See G.W. Leibniz, Meditationes de cognitione, veritate et ideis, Ger. Ph., vol. IV, p. 423.
12) Ivi, p.  424.
         13) G. Micheletti, I pensieri sordi e l’inconscio, Rome, 1991; on the close correlation between the two expressions one see, in particular, the pages 113-234.
14) Ovidio, Metamorphosis, book VII, vv. 20 - 21, quoted by Leibniz in Noveaux Essais, book II,  chapter 21, § 35 ; Ger.  Ph., V, p. 171.
15) B. Spinoza, Ethic, part IV, proposition XVII and preface.
16) G.W. Leibniz, Nouveaux Essais, book II, cap. 21, § 35 ; Ger. Ph., V, p. 171.
17) G.W. Leibniz, Essais de Teodicée, art. 311 ; Ger. Ph., VII, p. 301.
18) Ibidem.
19) Ibidem.
20) G. W. Leibniz, Nouveaux Essais, book II, cap. 21, § 35 ; Ger.  Ph., V, p. 171.
21) G. W. Leibniz, Commentatiuncula de iudice controversarum, AK., VI R. I B, p. 551.
22) G.W. Leibniz: Nouveaux Essais, book II, cap. 21, § 35 ; Ger.  Ph. V, p. 171.
       23) Ibidem. A major attention could also render, according to Malebranche, our perceptions clearer and more distinct  and consent us to see with a full vision the ties necessary among all the passages of our deductions. To succeed in this, it is however indispensable to realise that the spirit “does not pay the same attention to all the things it perceives, as one dedicates much more to those that touch it, that modify it and involve it than to those who are present for it, but which do not touch it and do not belong to it”. (Malebranche, De la Recherche de la Vérité, Book VI, part I, chapter.  2, Paris, 1979, pp. 594 – 595, my translation).
24) See G.W. Leibniz, Meditationes de cognitione, veritate et ideis, Ger. Ph., vol.  IV, p. 423.
25) M. Dascal , La semiologie de Leibniz, Paris, 1978, p. 180.
26) M.  Heidegger, Der Sats vom Grund, Tubingen 1958, pp. 168 e 192; see A. Robinet, Leibniz und Heidegger, Atomzeitälter oder Informatikzeitälter, in «Studia Leibnitiana»  Band VIII/2, 1976, p. 255.
27) “Any kind of  knowledge does not procure to he who knows that the maximum good is imperfect. In the same way any intellection which does not aid the vision or the enjoyment of the Supreme Being from the intelligent creature is imperfect” (Leibniz to Altorf, 1663, AK, VI R. I B, p. 159-160; my translation).
28) G.W. Leibniz, Nouveaux Essais, book II, cap. 21, § 36 ; Ger.  Ph.  V, p. 176.
29) Ivi, cap. 20, §  6 ; Ger.  Ph.,  V, p. 150.
30) Ivi, cap. 21, § 37; Ger.  Ph., V, p. 176.
31) See  ibidem.
32) Ivi, book II, cap. 21, § 36; Ger.  Ph. V, p.  175.
33) Ivi, book II, cap. 1, § 11, Ger.  Ph.  V, p. 103.
34) ibidem.
35) Ivi, book II, cap. 1, § 22 ; Ger.  Ph., V, p. 108.
36) Ibidem.
37) See  Ivi, book II, cap. 6, § 2 ; Ger.  Ph., V, p. 379.
38) See F. Lamy:  De la connaissance de soi même, quoted edition, t. II, pp. 337-338.
39) Ivi,  t. IV, pp. 74, 245-246, 272-273.
40) See Ivi, t. III, pp. 383 - 384.
41) Ivi, book II, chapter 21, § 35 ; Ger.  Ph., V, p. 173. In the same passage Teofilo sustains not wanting to provide moral precepts, but try to perceive  “reflecting on the course of our soul the source of our weakness, of which knowledge obtains at the same time the discovery remedies” (ibidem).
42) See. G.W. Leibniz, Essais de Teodicée, art. 311; Ger.  Ph.  VI, p.  301; (italian trans.)  OB., vol. I, p. 665.
43) S. Freud, L’inconscio, § 2, italian traslation, in Opere di S. Freud, Torino, 1976, vol. VIII, pp. 58-59.
44) See. G. Micheletti: quoted work pp. 186-188, note 19; e J Laplanche e J. B: Pontalis: L’enciclopedia della psicoanalisi, italian traslation, Bari, 1973, see entry “Inconscio” ( “Unconscious”) .
         45) Relative to the report that exists in Leibniz between the expression “symbolic knowledge” and “blind  
    knowledge”, see G. Micheletti, quoted work, in particular pp. 147-149 e 150-164.


Descartes R., Meditationes de prima philosophia, in qua Dei existentia et animae immortalitas demonstrantur,   
in  Oeuvres, edited by C. Adam e P. Tannery  ( = AT),  Paris 1897- 1913, vol. IX.
Freud S., L’inconscio, italian traslation, in Opere di S. Freud, Turin , 1976.
Dascal M., La semiologie de Leibniz, Paris, 1978
Heidegger M., Der Sats vom Grund, Tubingen 1958
Lamy F., De la connaissance de soi même, second edition, Paris 1701, in VI vols.
Laplanche J. e Pontalis J.B., L’enciclopedia della psicoanalisi, italian traslation Bari, 1971.
Leibniz G.W., Nouveaux Essais, in Ger. Ph., Vol. V.
Leibniz G.W., De arte combinatoria, in  Ger. Ph. vol. IV
Leibniz G.W., Essais de Teodicée, in  Ger.  Ph.  VI.
Leibniz G.W., Meditationes de cognitione, veritate et ideis, in Ger. Ph., vol. IV .
Leibniz G.W., Commentatiuncula de iudice controversarum, in AK, VI R. I B;
Leibniz G.W., Demonstratio propositionum primarium,  in AK, VI R. II B.
Leibniz G.W., Accessio ad aritmeticam infinitorum (end 1672), in AK,  II R. I B.
Leibniz G.W., Termini Sempliciores, in Grua.
Malebranche N., De la recherche de la vérité, Paris, 1962.
Micheletti G., I pensieri sordi e l’inconscio, Rome, 1991.
Ovidio Nasone, Metamorphosis.
     Robinet A., Leibniz und Heidegger, Atomzeitalter oder Informatikzeitalter, in «Studia
                         Leibnitiana»  Band VIII/2, 1976
Rodis-Lewis G., Le problème de l’inconscient et le cartésianisme, Paris, 1950.
Spinosa B., Etica, italian traslation Torino, 1978 (first edition 1959).



The passages where the expressions “blind thought” or “blind thoughts” appear, in chronological order, are:

De arte combinatoria (1666); Ger. Ph. IV, p. 35.
Commentatiuncula de Judice controversiarum (1669-1671); Ak., VI R., II B, p. 481.
Accessio ad Arithmeticam infinitorum, (Leibniz to Jean Gallois, fine 1672); Ak. II R, I B, p. 228.
Meditationes de Cognizione, Veritate et Ideis (1684); Ger. Ph. IV, p. 423.
Termini sempliciores (about 1680-1684); Grua, p. 543.

The expression “deaf thought” or “deaf thoughts” appear in the following places:

In a letter to Princess Sophia in 1697; Ger. Ph. VII, p. 555;

In Essays of Teodicea, second part, at 311and in the index edited by Leibniz in the same work, Ger. Ph. VI, p. 301;


In New essays on human intellect in the following passages:

Book II, cap. XXI, § 35-37 e 63.
Book II, cap. XXIX, § 11-12.
Book III, cap. I, § 1.
Book III, cap. II, § 2.
Book IV, cap. VI, § 2.

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