Hume's Philosophy: Ideas, Impressions, and Perceptions

Hume's Philosophy: Key Concepts

Ideas

Ideas are a kind of perception that are less lively and depend on sense impressions. They are based on experience, which Hume argues is the only possible area of knowledge.

Ideas are copies or derivations of our impressions and meanings derived from internal or external sources.

• Hume attaches extreme importance to the law of association of ideas. Human nature has a tendency to link ideas together. These laws are resemblance, contiguity, and cause-and-effect relationship.
• Imagination plays a big role in the combinations of ideas that we create, and often follows the force of habit.
• The association between ideas helps to explain concepts like the idea of substance and the idea of subject. Hume criticizes ideas that do not precede experience and cannot be reduced to an impression or perception.

Impressions

Impressions are the first data to change our mind, giving rise to other perceptions that appear there.

They are sensations, passions, and emotions that act with strength and vitality in our mind.

Impressions are divided in two ways:

• Impressions of sensation or reflection: whether resulting from the external world or our own mind.
• Impressions simple or complex: depending on their complexity.

Perception

Hume called perception everything that we find in our mind, both the objects of our experiences and the experiences themselves.

Perceptions have several classifications. They are divided into impressions and ideas, depending on their origin, and into simple or complex.

Hume uses two criteria to distinguish impressions from ideas:

1. Intensity: impressions have more strength and vivacity than ideas.
2. Origin: ideas or images are attenuated copies of impressions.

Questions of Fact

Knowledge of questions of fact refers to the empirical world and is based on experience.

It does not allow a strict knowledge such as mathematics or logic, but is based on probability because the opposite of each event is always possible.

Facts are the happenings in the world, the behavior of things as perceived by our senses. Experience is the collected set of facts.

• Some facts happen after others, but the bond between them is contingent and can be otherwise.
• No question of fact is necessary regarding the empirical way of things and not be an idea.
• For Hume, no question of fact can be contradictory or absurd, though it may seem strange. For example, after the night, the sun does not appear (it is strange because we are used to it coming out, but it is not absurd; it may be a cloudy day).

Relationships Between Ideas

Relationships between ideas are reached through the exercise of reason, not by observation and experience. Their truth depends on the principle of contradiction, but not on questions of fact.

• They establish necessary relationships and do not refer to physical things but to our own ideas.
• The truth cannot be refuted by any experience and is discovered through thought and does not depend on any of the things that exist in the universe.

Phenomenon

Phenomenon is a philosophical theory according to which no knowledge is possible for something different from our own perceptions.

Hume believed that this philosophical position is the only reasonable one but contrary to natural beliefs or common sense.

He reached this conclusion by noting that in the act of perception, the object perceived is not included as an object in perception but presents itself as something outside the mind.

For example, when I say I see a table, what I actually have in my mind is a whole variety of visual sensations that I associate with each other (color, shape, size...).

It is not possible then to know reality as it can be in itself; we would have to accept that reality is rather the sum of our own experiences.

To say that my perception is valid, I would have to compare it with reality itself, a fact which is impossible since I cannot leave my own mind to make that comparison.