Fusion power is speculative and experimental. I think it is reckless to assume that the fusion problem will be cracked, but I’m happy to estimate how much power fusion could deliver, if the problems are cracked.
The risks are far greater to your child of not getting immunized than any kind of speculative potential relationship between the vaccine and the development of autism.
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?
I pledge allegiance to the living, and I will defend art from history. I will rescue art from the future, from its attrition into taste, and from the speculative notion that it will become more valuable with time.
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.
Thus the same object may supply a practical perception to one person and a speculative one to another, or the same person may perceive it partly practically and partly speculatively.