The Gifford Lectures at Glasgow, 1916-1918, Vol II.
Book III. The Order and Problems of Empirical Existence
Chapter IX. Value
D. Beauty and Ugliness
...It is the paradox of beauty that its expressiveness belongs to the beautiful thing itself and yet would not be there
except for the mind.
...Perhaps the simplest way to understand beauty is to contrast the beautiful object on the one hand with a percept and on the other with an illusion. As contrasted with the percept, the beautiful is illusory, but it differs from illusion in that it is not erroneous. Considered from the point of view of cognition, the beautiful object is illusory for it does not as an external reality contain the characters it possesses for the aesthetic sense.