This one could do with expansion and/or contextualisation. A quick Google only turns up several pages of just the bare quote (including on a National Institue of Health .gov page!) - what was the original source? Anyone?
Well, I deliberately left out the source because I didn't think it would play well in this Peoria of thought -- it's from his book of essays Farewell to Reason. Link to gbooks with some context.
You all know the rules: