An interview with Paul Kurtz from Free Inquiry in 1982:
Asimov: If we insist on the Bible’s being literary true, then we must abandon the scientific method totally and completely. There’s no way that we can at the same time try to discover the truth by means of observation and reason and also accept the Bible as true.
Kurtz: So what is at stake in this debate between evolution and creationism is not simply the principle of evolution in regard to living things but the whole status of the sciences themselves?
Asimov: That is what I believe. But I have letters from creationists who say that they don’t deny the scientific method, that they are just trying to examine the inconsistencies in the evidence presented by the evolutionists. However, that is not what should be the chief job of the creationists. What they should do is present positive evidence in favor of creationism, which is something they never do. They confine themselves to pointing out inconsistencies in the evolutionary view, not hesitating to create those inconsistencies by distortion and, in my opinion, in some cases by outright fraud. Then they say that they have “proved” that evolutionary theory is false, and therefore creationism is correct.
Kurtz: Isaac, how would you describe your own position? Agnostic, atheist, rationalist, humanist?
Asimov: I am an atheist, out and out. It took me a long time to say it. I’ve been an atheist for years and years, but somehow I felt it was intellectually unrespectable to say one was an atheist, because it assumed knowledge that one didn’t have. Somehow it was better to say one was a humanist or an agnostic. I finally decided that I’m a creature of emotion as well as of reason. Emotionally I am an atheist. I don’t have the evidence to prove that God doesn’t exist, but I so strongly suspect he doesn’t that I don’t want to waste my time.
How could the inspired man know that the communication was
received from God? If God in reality should appear to a human
being, how could this human being know who had appeared? By what
standard would he judge? Upon this question man has no experience;
he is not familiar enough with the supernatural to know gods even
if they exist. Although thousands have pretended to receive
messages, there has been no message in which there was, or is,
anything above the invention of man. There are just as wonderful
things in the uninspired as in the inspired books, and the
prophecies of the heathen have been fulfilled equally with those of
the Judean prophets. If, then, even the inspired man cannot
certainly know that he is inspired, how is it possible for him to
demonstrate his inspiration to others? The last solution of this
question is that inspiration is a miracle about which only the
inspired can have the least knowledge, or the least evidence, and
this knowledge and this evidence is not of a character to
absolutely convince even the inspired.
Robert Green Ingersoll – “Why I Am Agnostic”