Is human knowledge trustworthy

4.2.1 Epistemology

Locke dedicates his main work, the "Treatise on the human understanding" (1689), to epistemology. This is considered a milestone of modern empiricism. It deals with a key question of the Enlightenment: Is there a knowledge without the person first coming into contact with the outside world? The rationalists such as Descartes, Spinoza or Leibniz had claimed that knowledge from pure thought was possible. Man is therefore not dependent on experience in order to have knowledge about the world and its logical structure. Descartes, for example, sees the existence of God as an "innate idea" (Descartes 1992, pp. III. And V.). In contrast, the empiricists reject knowledge that is independent of experience. The human mind is first of all a "tabula rasa". Knowledge only comes about through (sensual) experiences.
The "treatise" is divided into four parts: The first book is about Locke's rejection of the rationalistic thesis about innate ideas, the second book deals with ideas as an object of knowledge, the third book contains a linguistic-philosophical treatise and the fourth book one Theory of knowledge. Locke is - alongside David Hume (1711–1776) and George Berkeley (1685–1753) - a prominent representative of modern empiricism. It is helpful to distinguish between a “genetic” and a “truth-theoretical” empiricism (for this distinction see (Specht 2007, p. 39 ff.)). “Genetic” empiricism is linked to the assertion that ideas are derived from experience come. So it relates to the origin of the ideas. The “truth-theoretical” empiricism, on the other hand, means the assertion that the truth of statements must be checked on the basis of experience. There is evidence of both claims in Locke. The "genetic" aspect of empiricism becomes clear here:

“Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas; How comes it to be furnished? ... Whence has it all the materials of Reason and Knowledge? To this I answer, in one word, From Experience " (Essay II, ch. 1, 104).

The origin of ideas (idea; Imagination) is experience. For Locke there are no innate ideas, neither in relation to theoretical knowledge nor to morality (cf. Essay I, ch. 3, 65 ff.). For Locke this is evident: For example, not all peoples had a concept of God. Locke distinguishes between empirical knowledge as follows: On the one hand, there is knowledge that arises from sensory experience:

"First, Our senses, conversant about particular sensitive objects, do convey into the mind, several distinct Perceptions of things, according to those various ways, wherein those objects do affect them: And thus we come by those Ideas, we have of Yellow, White, Heat, Cold, Soft, Hard, Bitter, Sweet, and all those which we call sensible qualities, which when I say the senses convey into the mind, I mean, they from external objects convey into the mind what produces there those Perceptions. This great Source, of most of the Ideas we have, depending wholly upon our Senses, and derived by them to the Understanding, I call SENSATION“(Essay II, ch. 1, 105).

So “genetic” empiricism involves you sensualism with a. However, Locke goes beyond pure sensualism. Knowledge is not only based on external experience (perception of external objects; sensation), but also on internal experience (reflection):

Secondly, The other Fountain, from which Experience furnishes the Understanding with Ideas, is the Perception of the operations of our own minds within us, as it is employ’d about the Ideas it has got; which operations, when the soul comes to reflect on, and consider, do furnish the understanding with another set of Ideas, which could not be had from things without: and such are, Perception, Thinking, Doubting, Believing, Reasoning, Knowing, Willing, and all the different actings of our own Minds; which we being conscious of, and observing in our selves, do from these receive into our understandings, as distinct Ideas, every Man has wholly in himself: And though it be not Sense, as having nothing to do with external objects; yet it is very like it, and might properly enough be call'd internal sense "(Essay II, ch. 1, 105).

sensation and reflection are therefore for Locke the sources of ideas and thus of knowledge in general. Through the processes of sensation and reflection, “simple ideas” come about. As an example of a simple idea, Locke cites the idea of ​​firmness, which one experiences through contact and resistance of a body (Essay II, ch. 4, 122 ff.). Simple ideas depend on man's endowment with sense organs; the mind behaves receptively-passively here, it receives impressions (Essay II, ch. 12, 163). The mind can, however, also actively relate to simple ideas and transform the existing material of ideas into new, “complex ideas” through its own operation of thinking. The complex ideas thus arise through thinking reworking of the simple ideas. This reworking of simple ideas into complex ideas is done in three ways:

"The Acts of the Mind wherein it exerts its Power over its simple Ideas are chiefly these three, 1. Combining several simple Ideas into one compound one, and thus all Complex Ideas are made. 2. The 2d. is bringing two ideas, whether simple or complex, together; and setting them by one another, so as to take a view of them at once, without uniting them into one; by which way it gets all its Ideas of Relations. 3. The 3d. is separating them from all other Ideas that accompany them in their real existence; this is called Abstraction: And thus all its General Ideas are made ”(Essay II, ch. 12, 163).

Simple ideas become complex ideas with the help of active intellectual activity. Locke differentiates between the types of intellectual activity in connection, relation and abstraction. Locke divides the resulting “complex” ideas into modes, substances and relations (Essay II, ch. 12, 164). For Locke, "modes" are complex ideas that do not exist on their own, but are dependent on substances (e.g. the beauty of something). "Substances" are defined as ideas that represent certain individual things that exist for themselves, such as people (cf. Essay II, ch. 23, 295 ff.). The phrase “represent” expresses that Locke substances, as general terms, are not thought of as existing. Locke is - like Hobbes - Nominalistfor which the general terms exist only in language, but not in reality. Finally, Locke calls “relations” a complex idea. What is meant are relationships between simple ideas, such as cause and effect (cf. Essay II, ch. 26, 324 ff.).
After Locke described the object of knowledge in the second book in the ideas, he is concerned with a theory of knowledge in the fourth book of the "treatise". Our ideas are the subject and limitation of our knowledge:

"Since the Mind, in all its Thoughts and Reasonings, has no other immediate Object but its own Ideas, which it alone does or can contemplate, it is evident, that our Knowledge is only conversant about them" (Essay IV, ch. 1 , 525).

So what is knowledge? The nominalist Locke can only give the following answer:

"Knowledge then seems to me to be nothing but the perception of the connexion and agreement, or disagreement and repugnancy of any of our ideas" (Essay IV, ch. 1, 525).

Here you can also find the "Truth-theoretical" aspect of empiricism, i.e. the compatibility of a statement with empirical knowledge as a truth criterion:

"’ This therefore the actual receiving of Ideas from without, that gives us notice of the existence of other things, and makes us know, that something doth exist at that time without us, which causes that Idea in us, though perhaps we neither know nor consider how it does it: For it takes not from the certainty of our Senses, and the Ideas we receive by them, that we know not the manner wherein they are produced ”(Essay IV, ch. 11, 630f.).

Locke gives an interesting example of the certainty of the existence of external things:

"[W] help I write this, I have, by the paper affecting my eyes, that Idea produced in my Mind, which whatever Object causes, I call White; by which I know, that that quality or accident (i.e. whose appearance before my eyes, always causes that Idea) doth really exist, and hath a Being without me. And of this, the greatest assurance I can possibly have, and to which my Faculties can attain, is the Testimony of my Eyes, which are the proper and sole Judges of this thing, whose Testimony I have reason to rely on, as so certain , that I can no more doubt, whilst I write this, that I see White and Black, and that something really exists, that causes that Sensation in me, than that I write or move my Hand; which is a Certainty as great, as humane Nature is capable of, concerning the Existence of any thing, but a Man’s self alone, and of GOD "(Essay, IV, ch. 11, 631).

Question 14: Go into the terms “empiricism”, “sensualism” and “nominalism” and also refer to John Locke's epistemology in your answer!

Answer (click here)

“Empiricism” is understood to mean that all knowledge is ultimately based on experience. Modern empiricism was represented in particular by John Locke (1632–1704), David Hume (1711–1776) and George Berkeley (1685–1753). In epistemology, empiricism turns against rationalism. The latter asserts the existence of innate ideas. In contrast, empiricism regards the mind as a “tabula rasa” or “white paper”. Only experience leads to contents of the mind.
John Locke is a leading exponent of modern empiricism. His epistemology can be found in the main work "Treatise on the human mind" (An Essay Concerning Human Understanding, 1689). For Locke, the object of knowledge is ideas. Ideas initially come from external sensory perception (such as colors). Locke calls these “simple ideas”. In this respect, Locke's empiricism is a sensualism. Simple ideas can be transformed into "complex ideas" (example: beauty) through further mental processing, e.g. through abstraction. Locke formulates a nominalistic position because for him general terms (such as human, beauty) cannot claim an existence independent of language.

Question 15: Name at least two objections to classical empiricism!

Answer (click here)

There have been three main objections to the view that all knowledge comes from experience:
1. Concept of truth: The necessary truth of mathematical theorems, such as 1 + 1 = 2, cannot be justified empirically (Pfister 2011, p. 114). Thus empiricism cannot formulate necessary truths.
2. Induction problem: Empiricism also has to deal with the induction problem. The induction problem was largely formulated by David Hume: From individual observations we cannot obtain any certainty about all future observations. An inductive conclusion does not have the certainty of a logical conclusion. Hume's example is this: “Suppose, for example, that I have found in long observation that out of twenty ships that put out to sea, only nineteen return. Right now I see twenty ships leaving port. Then I simply transfer my previous experience to the future, so imagine nineteen of these ships returning undamaged and one sinking "(Hume , A Treatise of Human Nature, Book I: Of the Understanding). From the observation that in the past out of twenty ships only nineteen have returned, it does not follow with logical necessity that this will also be the case in the future. Since the synchronization of history cannot be proven, the induction problem addresses a lack of certainty in empiricism. 3. Kant's critique of empiricism: Sensuality is a necessary condition for knowledge, but not a sufficient one. Kant's saying is famous: “Without sensuality, no object would be given to us and without understanding no one would be thought. Thoughts without content are empty, views without concepts are blind ”(KrV, B 75). We have succumbed to a “myth of the given” (Sellars) when we think that mere contact with the world is insightful. Knowledge according to Kant requires both elements: the recording of sensory data and the understanding of its own (cf. more closely (Höffe 2011, p. 85 f.)). Among other things, the criticism of the scientific worldview is based on this objection by Kant: Theories about the world cannot be inferred from observation alone. Rather, scientific theories are constructions, creations of thought. The scientific worldview mixes model and reality.