"We have failed to protect science against speculative extensions of nature, continuing to assign physical and mathematical properties to hypothetical entities beyond what is observable in nature."
"Evolution is a bankrupt speculative philosophy, not a scientific fact. Only a spiritually bankrupt society could ever believe it. Only atheists could accept this Satanic theory."
"True science is never speculative it employs hypotheses as suggesting points for inquiry, but it never adopts the hypotheses as though they were demonstrated propositions."
"I fear that, in the end, the famous debate among materialists, idealists, and dualists amounts to a merely verbal dispute that is more a matter for the linguist than for the speculative philosopher."
"All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?"
"He was a dreamer, a thinker, a speculative philosopher... or, as his wife would have it, an idiot."