Principle of causality
29th September 2020
At most two classes of knowledge:
All of the possible sources of knowledge, therefore, are
- relations of ideas: relationship of ideas not immediately intuitively connected among each other. They can be true regardless o reality
- matters of fact: propositions which can definitely be denied without contradiction. They describe the situation we can experience in the world, they speak about the world.
In Descartes, Maths is real, it actually exists, while in Hume it is just a tool we may use to understand it. Furthermore, in Descartes Philosophy is a normative science, while in Hume its purpose is to clarify what’s already there.
We don’t have access to the actual essence of the Universe, since we can’t experience with our senses the core of reality. Yet, it is not a problem, we don’t need metaphysics. We don’t need to understand the core, we need to understand what we have. It’s not important that we impose principles to other people, as we think it’s better to think. The key aim is to be a scientist and try to understand what it’s necessary to understand.
We don’t have proof of objectivity of perceptions, but we have different types of skepticism.
Even if we can’t be sure of objectivity, we can communicate with each other, so we can exchange opinions on everyday life. In normal life we don’t need philosophical questions.
Hume believed in progress, but we can’t have the last word on everything; we need to be open to new knowledge, for this reason we can’t be tied to our metaphysical notions.
We can’t consider all ideas mere copies of impressions. Ideas and impressions are combined by means of imagination. Our imagination doesn’t act completely freely, it follows some rules1
Maths only as an abstraction when we generalize and abstract notions of the single objects we experience.
Platonic point of view (Maths is real) vs Aristotelian point of view (Maths is an abstraction). Different perspectives: later on every philosopher had to “pick a side”.
Hume’s critic to the principle of cause and effect
The principle of cause and effect is the most important one, since through this we can extend our knowledge of the world we can get through our senses.
(Cause and reason were conceived as synonyms at the time).
How do we know the principle of cause and effect? How do we get the knowledge of it? How do we understand the cause of cause and effect? Why is it the most important principle?
The certainty of this principle can’t come by reasoning only. If we look at an object for the first time, we can’t understand its causes and the possible effects.
Sometimes we don’t need experience to infer the causes of some events (Popper)
is in the preface of the principles of classical philosophy by Newton ↩