Modes and Substances

Modes and Substances are Just Simple Ideas Connected Together by the Mind

Some philosophers:

• founded so much of their reasonings on the distinction of substance and accident, and
• imagined we have clear ideas of substance and accident.

Is the idea of substance derived from the impressions of sensation or of reflection?

If it is conveyed to us by our senses, which of them and how?

If it is perceived by:

• the eyes, it must be a colour,
• the ears, a sound,
• the palate, a taste, and so of the other senses.

Impressions of reflection

No one will assert that substance is a colour, sound, or a taste.

The idea of substance must therefore be derived from an impression of reflection, if it really exists. But the impressions of reflection resolve themselves into our feelings. None of these can possibly represent a substance. We therefore have no idea of substance, distinct from the idea of a collection of particular qualities. We have no other meaning when we talk about it. The idea of a substance and mode is nothing but a collection of simple ideas that:

are united by the imagination, and have a particular name assigned them for us to recall that collection. The difference between substance and mode is that the qualities of a substance refer to an unknown something.

This something is supposed to: exist essentially in that substance, or at least be inseparably connected by the relations of contiguity and causation. The effect of this is that whatever new simple quality that we find connected with the rest, we immediately comprehend it among them even if we did not realize it intially.

Thus, our idea of gold may at first be a ‘yellow colour’, ‘weight’, ‘malleableness’, and ‘fusibility’. But after discovering its dissolubility in hydrochloric acid, we add ‘dissolubility’ to these. We then suppose ‘dissolubility’ to be part of the complex idea of gold from the start. This union: is regarded as the chief part of the complex idea, allows whatever quality occurs afterwards, and includes that quality to those other qualities that were presented before it. This union cannot happen in modes.

The simple ideas which form modes either represent: qualities which are not united by contiguity and causation but are dispersed in different subjects, or qualities in which the uniting principle is not the foundation of the complex idea. For example, the idea of a dance is an instance of the first kind of modes. The idea of beauty is an instance of the second. Such complex ideas cannot receive any new idea without changing the name of the mode.