“Could you give me an example?”
“If you burn yourself on a hot oven, you get an immediate ‘impression.’
Afterward you can recollect that you burned yourself. That impression insofar as it is
recalled is what Hume calls an ‘idea.’ The difference is that an impression is stronger
and livelier than your reflective memory of that impression. You could say that the
sensation is the original and that the idea, or reflection, is only a pale imitation. It is
the impression which is the direct cause of the idea stored in the mind.”
“I follow you—so far.”
“Hume emphasizes further that both an impression and an idea can be either
simple or complex. You remember we talked about an apple in connection with
Locke. The direct experience of an apple is an example of a complex impression.”
“Sorry to interrupt, but is this terribly important?”
“Important? How can you ask? Even though philosophers may have been
preoccupied with a number of pseudoproblems, you mustn’t give up now over the
construction of an argument. Hume would probably agree with Descartes that it is
essential to construct a thought process right from the ground.”
“Okay, okay.”
“Hume’s point is that we sometimes form complex ideas for which there is no
corresponding object in the physical world. We’ve already talked about angels. Pre-
viously we referred to crocophants. Another example is Pegasus, a winged horse. In
all these cases we have to admit that the mind has done a good job of cutting out and
pasting together all on its own. Each element was once sensed, and entered the theater
of the mind in the form of a real ‘impression.’ Nothing is ever actually invented by
the mind. The mind puts things together and constructs false ‘ideas.’ “
“Yes, I see. That is important.”
“All right, then. Hume wanted to investigate every single idea to see whether it
was compounded in a way that does not correspond to reality. He asked: From which
impression does this idea originate? First of all he had to find out which ‘single ideas’
went into the making of a complex idea. This would provide him with a critical
method by which to analyze our ideas, and thus enable him to tidy up our thoughts
and notions.”
“Do you have an example or two?”
“In Hume’s day, there were a lot of people who had very clear ideas of ‘heaven’
or the ‘New Jerusalem.’ You remember how Descartes indicated that ‘clear and
distinct’ ideas in themselves could be a guarantee that they corresponded to something
that really existed?”
“I said I was not especially forgetful.”
“We soon realize that our idea of ‘heaven’ is compounded of a great many
elements. Heaven is made up of ‘pearly gates,”streets of gold,”angels’ by the score
and so on and so forth. And still we have not broken everything down into single
elements, for pearly gates, streets of gold, and angels are all complex ideas in them-
selves. Only when we recognize that our idea of heaven consists of single notions
such as ‘pearl,”gate,”street,”gold,”white-robed figure,’ and ‘wings’ can we ask our-
selves if we ever really had any such ‘simple impressions.’ “
“We did. But we cut out and pasted all these ‘simple impressions’ into one
idea.”
“That’s just what we did. Because if there is something we humans do when we
visualize, it’s use scissors and paste. But Hume emphasizes that all the elements we
put together in our ideas must at some time have entered the mind in the form of
‘simple impressions.’ A person who has never seen gold will never be able to