The subjects treated are deep enough to demand the serious attention of any one; and they are subjects of fascinating interest.

That they are treated simply and clearly does not mean that they are treated superficially.

Indeed, when a doctrine is presented in outline and in a brief and simple statement, its meaning may be more readily apparent than when it is treated more exhaustively.

For this reason, I especially recommend, even to those who are well acquainted with philosophy, the account of the external world contained in Chapter IV.
For the doctrine I advocate I am inclined to ask especial consideration on the ground that it is, on the whole, a justification of the attitude taken by the plain man toward the world in which he finds himself.

The experience of the race is not a thing that we may treat lightly.
Thus, it is maintained that there is a real external world presented in our experience--not a world which we have a right to regard as the sensations or ideas of any mind.