Hume says that ideas comes from impression and matters of fact can't have impression. So is it according to Hume that we do not have any impression of things in the daily life such as table, chair? Then why does he give the example of blue color where most of the ideas of its shades come from impression?
That sounds strange. Send the citation. Maybe it was about a qualified form of impressions, such as emotional impressions, rather than sense impressions.– Gonçalo MabundaNov 13, 2017 at 2:17
2Not clear; see Hume's Account of the Mind for the distincion between impressions and ideas and Hume on Causation for the distinction between relations of ideas and matters of fact.– Mauro ALLEGRANZANov 13, 2017 at 10:14
Impressions are "in" the mind through our five senses. Matters of fact are the facts "out there": propositions concerning matters of fact depends on the way the world is.– Mauro ALLEGRANZANov 13, 2017 at 10:16
2Aren't impressions elements or objects of the mind, something like what used to be called 'sense data' ? If so, we don't perceive - directly experience - tables and chairs. Our knowledge of them as 'matters of fact' is the product of habitual or customary associations : the association of ideas derived from impressions. That's my view, entirely prone to error, of what Hume believes.– Geoffrey Thomas ♦Nov 13, 2017 at 10:33
@Geoffrey Thomas: that tallies with what little I've read of Hume.– Mozibur UllahNov 15, 2017 at 13:12
Hume's view is that ideas derive from impressions, meaning roughly and to take an example that I cannot have the idea of blue unless I have had sensory experience (impression) of the colour. The idea is causally dependent on the impression. He doesn't keep strictly to this view in his example of the missing shade of blue. Hume concedes that if we were to have sensory experience of every shade of blue except one, we could imagine - form an idea - of what the missing shade of blue would be like. ('Treatise of Human Nature', 1739-40, I.1.1.)
After receiving an impression of blue I can retain the experience in memory; I thus acquire an idea of the colour, blue. There are no innate ideas; all ideas derive from impressions. This is a part of Hume's empiricism.
'Matters of fact' are broadly limited to beliefs about the existence of perceptible objects - chairs, tables, statues, trees and such like. Such beliefs have two features. The first is that we cannot establish them by reason, by logic, but only by perception. The other is that 'the contrary of every matter of fact is still possible; because it can never imply a contradiction' ('Enquiry Concerning Human Understanding, 1748, IV.1) The Statue of Liberty exists but it is logically possible for it not to do so. By contrast a triangle cannot exist without its having three sides and three internal angles; a triangle without three sides and three internal angles is in Hume's language a contradiction.
Hume never offers an explanation of how external objects, if there are any, cause our impressions to occur, nor does he try to show that there actually are any external objects to cause our impressions. In this sense we can't - or don't - have an impression of the external world but only (at best) an impression caused by an object in the external world.
It seems to me that you identify 'matter of fact' with 'external world'. I don't think this is quite right. A matter of fact is a perceptual belief based on our experience of impressions. But you are right (to repeat) that we do not have impressions of anything in the external world. Perhaps there is an external world and perhaps objects in it cause our impressions but of the external world itself we have no impressions.
Hume is an extremely elusive writer. There appears to be extreme clarity but on many points it is desperately hard to pin down his exact meaning. However, the above is my considered view about the relation of impressions to matters of fact. I believe it to be correct but as so often with Hume one must be tentative.
@wolf-revo-cats. You have an answer to your question on Hume,– Geoffrey Thomas ♦Jan 30, 2018 at 14:37