I wanted to follow up on a reference I made on the episode for folks who want to know more about Russell's epistemology:
His book The Problems of Philosophyis an easy-reader intro to his take on traditional epistemological problems. Some of it will be familiar if you've listened to our episodes (from p. 42). For instance, he claims: "The faculty of being acquainted with things other than itself is the main characteristic of a mind," and uses this as an a priori refutation of idealism: the idealist confuses ideas and the objects (which we may know virtually nothing about) to which the ideas correspond.
One element of his epistemology which will sound familiar to fans of British empiricists is his distinction between knowledge by description and knowledge by acquaintance (from chapter 5):
We shall say that we have acquaintance with anything of which we are directly aware, without the intermediary of any process of inference or any knowledge of truths. Thus in the presence of my table I am acquainted with the sense-data that make up the appearance of my table--its colour, shape, hardness, smoothness, etc.; all these are things of which I am immediately conscious when I am seeing and touching my table. The particular shade of colour that I am seeing may have many things said about it--I may say that it is brown, that it is rather dark, and so on. But such statements, though they make me know truths about the colour, do not make me know the colour itself any better than I did before so far as concerns knowledge of the colour itself, as opposed to knowledge of truths about it, I know the colour perfectly and completely when I see it, and no further knowledge of it itself is even theoretically possible. Thus the sense-data which make up the appearance of my table are things with which I have acquaintance, things immediately known to me just as they are.
My knowledge of the table as a physical object, on the contrary, is not direct knowledge. Such as it is, it is obtained through acquaintance with the sense-data that make up the appearance of the table. We have seen that it is possible, without absurdity, to doubt whether there is a table at all, whereas it is not possible to doubt the sense-data. My knowledge of the table is of the kind which we shall call 'knowledge by description'. The table is 'the physical object which causes such-and-such sense-data'. This describes the table by means of the sense-data. In order to know anything at all about the table, we must know truths connecting it with things with which we have acquaintance: we must know that 'such-and-such sense-data are caused by a physical object'. There is no state of mind in which we are directly aware of the table; all our knowledge of the table is really knowledge of truths, and the actual thing which is the table is not, strictly speaking, known to us at all. We know a description, and we know that there is just one
object to which this description applies, though the object itself is not directly known to us. In such a case, we say that our knowledge of the object is knowledge by description.
All our knowledge, both knowledge of things and knowledge of truths, rests upon acquaintance as its foundation.
While there are problems with this view, it doesn't correspond to the super-simple "sense-certainty" view derided in Hegel's Phenomenology as I suggested on that episode. Note that on his account, have to have "acquaintance" with universals, contra Hume.