Albion Dreaming. A popular history of LSD in Britain (Revised Edition with a new foreword by Dr. Sue Blackmore)

I have many times tried to describe how simply taking a drug can change your whole perception of life, but it is rather like trying to explain colour to the blind. There are no terms of reference in ordinary life to help you to understand. And actually, I am torn between evangelising for the drug and warning everyone not to go within a million miles of it. I suppose the most simple and incredible fact about LSD is also the one that is hardest to believe: that what it reveals to you is not, as is popularly supposed, a hallucination, but an awe-inspiring glimpse of reality. Other drugs distort, but LSD gives you a reality far beyond words, or visual representation, or language. It is quite the reverse of seeing something that isn’t there. LSD disables some chemical filter in the brain that, in order to keep the world manageable, limits the amount of reality you can experience with your senses. An LSD trip allows ‘reality’ – and if you have never questioned what that is, you would after taking LSD – to flood in untrammelled. The result may be terrifying and it may be wonderful, but it will be more ‘real’ than anything

μg
Scientific symbol for microgram (one-millionth of a gram)