“The idea [imagination] of red which we form in the dark, differs only in degrees of intensity, not in nature, from the impression [perception] of red that strikes our eyes in sunshine.

If our imagination is vivid enough, we will think it is real and we use our imagination to create our perception of reality, which means, “We do not see things as they are, we see them as we are.” Our perception of the outside world is strongly influenced by what we believe.

When this mixed signal is strong or vivid enough to cross a reality threshold, we think it reflects reality. When the same object is perceived and imagined, the combined signal is stronger, so we are more likely to think this object is really out there.