Spinoza's Metaphysics and Hume's Epistemology: Core Concepts

Baruch Spinoza: Substance and Attributes

Spinoza's Concept of Substance

For Baruch Spinoza, reality is fundamentally Substance. He identifies God, or Nature (Deus sive Natura), as this singular, ultimate being. This Substance possesses an absolutely infinite number of attributes, each of which expresses an eternal and infinite essence. Substance itself is the ultimate cause.

Attributes and Modes

Spinoza emphasizes that attributes are fundamental aspects, akin to nouns, not mere adjectives or properties. An attribute is not simply a characteristic of Substance, but rather the very essence of the Substance itself, as conceived by the intellect – whether the finite understanding of man or the infinite understanding of God. Attributes are inherent in their Substance and are not predicated of it as a genus. While there is a real distinction between them, they cannot have causal communication among themselves.

Furthermore, Spinoza posits that souls and bodies are not independent substances, but rather modes of thinking substance and extended substance, respectively. Ultimately, God is the one Substance.

David Hume: Reason and Matters of Fact

Impressions and Knowledge

David Hume's philosophy delves into the nature of reason and matters of fact.

The fundamental elements that constitute our experience of the world are impressions. Each impression is distinct and separate from all others. Hume argues that there is no inherent reason for one impression to accompany or follow another; we only learn through experience which impressions tend to go together or follow each other. Hume suggests that what Plato might have considered mere 'divination' or empirical observation is, in fact, the only knowledge we can truly possess regarding matters of fact.

Two Kinds of Knowledge

However, Hume recognizes that mathematical knowledge cannot be regarded as a mere matter of association and habit. He states that our knowledge is of two kinds:

• Matters of Fact: These concern empirical observations and contingent truths about the world.
• Relations of Ideas: These involve purely formal and demonstrative knowledge, such as mathematics and logic, whose truths are discovered by reason alone and are necessarily true.

Outside of the relations of ideas, our knowledge is purely of 'matters of fact.' Thus, we have, on one hand, the purely formal and demonstrative knowledge of mathematics, and on the other, the positive empirical knowledge of the sciences, including politics (which Hume grouped with physics).

Hume's Legacy and the Vienna Circle

Hume developed a theory that remarkably resembles the principles accepted by members of the Vienna Circle around 1930. According to these principles, the natural sciences are based on assertions that only make sense if they refer to possible experience, while mathematics and logic are based on definitions. Hume often writes as if philosophy were a kind of associationist psychology. As for the truths of fact, they lack the necessity found in the formal sciences.