Lucia Oliveri

Immanuel Kant considers hypotheses as decisive for the assessment and development of scientific enquiry. Hypotheses guide the acquisition of data and the constructing of experiments. Yet, hypotheses are not reliable sources of knowledge since they can be mistaken for other forms of assumptions that may be unproductive for scientific discovery. Hypotheses are not reliable for two main reasons: either they prevent one starting a proper enquiry or lead one astray from it. The involvement of imagination within the process of hypothesis formation appears to be the source of mistakes since possible causes of observed phenomena may be merely feigned. This paper argues that Kant theorises a method of forming hypotheses that distinguishes hypotheses from other kinds of assumptions, especially fancies, at the moment of their formation. This method warrants that hypotheses are not feigned, according to Isaac Newton’s dictum, while preserving the fallible status of hypotheses. A hypothesis can turn out to be false on empirical testing, but this does not imply it was a fancy.

Cartesians equate all mental acts, such as sense-perceptions, affects, and desires, with conscious thought. This equation, Leibniz argues, leads Cartesians into a dilemma: either animals perceive, but then they also think; or they do not think, but they do not perceive either. To argue against the Cartesians that animals do perceive but do not think, Leibniz rejects the equation between perception and thought. In developing the distinction between perception and thought, I argue that Leibniz endorses the thesis that heightened and distinguished sense-perceptions are not the highest common factor between humans and animals. This perspective sheds new light on a much debated question in Leibniz scholarship: What is the relationship between consciousness, reflection, and apperception according to Leibniz’s theory of human and animal cognition?

Reasoning with diagrams is considered to be a peculiar form of reasoning. Diagrams are often associated with imagistic representations conveyed by spatial arrangements of lines, points, figures, or letters that can be manipulated to obtain knowledge on a subject matter. Reasoning with diagrams is not just ‘peculiar’ because reasoners use spatially arranged characters to obtain knowledge – diagrams apparently have cognitive surplus: they enable a quasi-intuitive form of knowledge. The present paper analyses the issue of diagrams’ cognitive value by enquiring into the tradition of symbolic cognition developed by Leibniz, Lambert, and Kant. The proposal resulting from this enquiry is to question the idea that the cognitive value of diagrams lies solely in allowing evidence for inferences. The imaginative dimension of diagrams connects reasoning to doxastic attitudes of meditation and enquiry.

There are two axes of Leibniz’s philosophy about bodies that are deeply inter- twined, as this paper shows: the scientific investigation of bodies due to the application of mathematics to nature – Leibniz’s mixed mathematics – and the issue of matter/bodies ide- alism. This intertwinement raises an issue: How did Leibniz frame the relationship between mathematics, natural sciences, and metaphysics? Due to the increasing application of mathe- matics to natural sciences, especially physics, philosophers of the early modern period used the reliability of mathematics to predict phenomena as the basis to infer the metaphysical outlook of nature. I argue that although Leibniz thought metaphysics must be scientifically informed and that mathematics is a valuable instrument to understand nature, metaphysics is more fun- damental than mathematics and natural sciences. By highlighting the foundational relation be- tween metaphysics and the sciences, this paper showcases an argument for the reality of bodies: the ideality of bodies, necessary for epistemic purposes, is not proof that they are not real. Keywords: Metaphysics, Application of Mathematics, Body, Idealism, Fundamentality.

G. W. Leibniz on Making Knowledge Sensible · G. W. Leibniz’s contribution to logic and a propositional theory of truth, based on the idea that concepts are composed of definitional notes, has been considered the core of his philosophical system and metaphysics. However, Leibniz thought that there are other forms of knowledge that are perceptual and, therefore, non-propositional and non-conceptual. This essay explores forms of non-conceptual knowledge and argues that they depend on the imagination. Despite the distinction between conceptual and non-conceptual forms of knowledge, there are two senses in which conceptual knowledge depends on non-conceptual knowledge : there is a constitutive sense in which non-conceptual knowledge has a constitutive function because it allows one to conceive of beings in concreto, and thus anchors human knowledge to reality ; there is a second sense in which non-conceptual knowledge has the function of making imaginable intellectual concepts that could not be other- wise represented by the human mind. The essay shows that these functions are interrelated.

Reasoning with diagrams is considered to be a peculiar form of reasoning. Diagrams are often associated with imagistic representations conveyed by spatial arrangements of lines, points, figures, or letters that can be manipulated to obtain knowledge on a subject matter. Reasoning with diagrams is not just ‘peculiar’ because reasoners use spatially arranged characters to obtain knowledge – diagrams apparently have cognitive surplus: they enable a quasi-intuitive form of knowledge. The present paper analyses the issue of diagrams’ cognitive value by enquiring into the tradition of symbolic cognition developed by Leibniz, Lambert, and Kant. The proposal resulting from this enquiry is to question the idea that the cognitive value of diagrams lies solely in allowing evidence for inferences. The imaginative dimension of diagrams connects reasoning to doxastic attitudes of meditation and enquiry.

Destutt de Tracy zielt darauf ab, zu erklären, wie inter- und transsubjektive Prozesse auf das einzelne Individuum wirken und es gestalten. Dafür braucht er eine externalistische Sprachtheorie und eine sensualistische kognitive Architektur, nach der Denken Empfinden ist. Das Denken ist relational, aber wird nicht auf kognitiver Ebene durch sprachähnliche Strukturen – durch die Syntax und Semantik einer Mentalsprache – implementiert. Obwohl Externalismus und sensualistische Architektur in eine inkohärente Theorie zu münden scheinen, versucht Destutt de Tracy die Spannung durch seine Entwicklungsgeschichte zu lösen, nach der Systematizität als assoziativ und symbolisch, aber nicht als sprachlich analysiert wird. Zum Denken ist eine Sprache notwendig, aber das Denken ist keine Mentalsprache. „[Wir sind] fast gänzlich das Werk Der Umstände, die uns umgeben.“ [Ideenlehre I, 273/388]

Eine Untersuchung der Präpositionen bei Leibniz kann aufgrund ihrer synkatego-rematischen Natur zeigen, in welchem Sinne die Sprache - als strukturiertes, bedeutendes Zeichensystem – das logische Verhältnis unter den Notionen ausdrü-cken kann, und damit der Zusammenhang zwischen Grammatik und Semantik einerseits, und Logik anderseits, erhellen. Meiner Ansicht nach bekommt auch Leibniz' Versuch des Aufbaus einer characteristica universalis dank dieser Per-spektive ein neues Forschungsinteresse. Um das Interesse für diese Redeteile zu wecken, werde ich zuvor in einem kurzen Exkurs die vorgängige Tradition dar-stellen. Das Ziel ist, zu zeigen, was die Unterscheidung zwischen Kategoremen und Synkategoremen innerhalb der Tradition der sogenannten Mentalsprache im-pliziert; welche Fragen ihre Analyse erhoben hat und was diese Unterscheidung bei einem für Leibniz wichtigen Denker, wie Joachim Jungius, bedeutet. Beson-ders zeige ich, wie die Unterscheidung Kategoreme – Synkategoreme der zwi-schen Begriff und modi des Begreifens entspricht. Danach analysiere ich die viel-fältige Betrachtung dieser Redeteile bei Leibniz in Bezug auf seine Zurückfüh-rung der Präpositionen auf eine räumliche Grundbedeutung. Zum Schluss versu-che ich zu zeigen, warum diese Redeteile als cogitationes caecae bei Leibniz interpretiert werden können und welche Schlüsse man aus dieser Bestimmung im Rahmen von Leibniz‟ Sprachphilosophie ziehen darf.

The topic of my paper is the virtual controversy between Leibniz and Lockeover concepts and ideas. At the end of the 17th century John Locke made a crucial contribution to semantics and philosophy: An Essay Concerning Human Understanding. The work represents a decisive turning point for the discussion about ideas and innatism. Indeed, Locke’s aim was to dismantle the Cartesian theory according to which ideas are innate in our soul. Against this onto-epistemological thesis, Locke maintains that all our knowledge starts off with experience: ideas are mental representations depending on subjects’ sensual experiences and reflection skills. Some years later, in his notes on Locke’s Essay, Leibniz writes that Locke dealt with a fundamental topic: human understanding and the limits of human knowledge (NE p. 4). All we can find out about the world is determined by answering the question about what we can know; nonetheless, Leibniz argues in favor of innate ideas. My thesis is that in his opinion Locke’s empiricism can be conciliated with the assumption that there are innate ideas.

In the years 1675-84, Leibniz sought to disprove Descartes’s account of clear and distinct perception by implementing a three-step argumentative strategy. The first part of the paper reconstructs the argument and highlights what aspects of Descartes’s epistemology it addresses. The reconstruction shows that the argument is based on conceivability errors. These are a kind of symbolic cognition that prove Descartes’s clear and distinct perception as introspectively indistinguishable from Leibniz’s symbolic cognition. The second part of the paper explores the epistemic implication of the indistinguishability between clear and distinct perception and symbolic cognition: the mind constitutively depends on products of the imagination. My conclusion addresses the role of the imagination in symbolization. Symbolization does not exceed imagination; it rather is an idealized use of cognitive surrogates, like characters, to submit to the imagination what is not subject to it.

Through the reconstruction of Leibniz's theory of the degrees of knowledge, this e-book investigates and explores the intrinsic relationship of imagination with space and time. The inquiry into this relationship defines the logic of imagination that characterizes both human and non-human animals, albeit differently, making them two different species of imaginative animals. Lucia Oliveri explains how the emergence of language in human animals goes hand in hand with the emergence of thought and a different form of rationality constituted by logical inferences based on identity and contradiction, principles that are out of reach of the imagination. The e-book concludes that the presence of innate principles in human animals transforms the way in which they sense-perceive the world, thereby constantly increasing the distinction between human and non-human animals. Keywords: human and non-human animals, Leibniz and Locke on ideas, Leibniz on bodies, Leibniz on conceivability, Leibniz on degrees of knowledge, Leibniz on degrees of perception, Leibniz on innate ideas, Leibniz on modality, Leibniz on similarity and congruence, Leibniz on space and time, Leibniz’s philosophy of language, theory of types