The first principle, when you don't know anything about the subject of a thesis, is to let the candidate talk, nodding now and then with an ambiguous smile. He thinks you know, and are counting his mistakes, and it unnerves him... the second principle of conducting an oral, … is to pretend ignorance, and ask for explanations of very simple points. Of course your ignorance is real, but the examinee thinks you are being subtle, and that he is making an ass of himself, and this rattles him.

There are no forbidden questions in science, no matters to sensitive or delicate to be probed, no sacred truths. That openness to new ideas, combined with the most rigorous, skeptical scrutiny of all ideas, sifts the wheat from the chaff. It makes no difference how smart, august, or beloved you are. You must prove your case in the face of determined, expert criticism. Diversity and debate are valued. Opinions are encouraged to contend–substantively and in depth.

Why do we put up with it? Do we like to be criticized? No, no scientist enjoys it. Every scientist feels a proprietary affection for his or her ideas and findings. Even so, you don’t reply to critics, Wait a minute; this is a really good idea; I’m very fond of it; it’s done you no harm; please leave it alone. Instead, the hard but just rule is that if the ideas don’t work, you must throw them away.

Humility is fundamental in science. I recall during an update meeting with my PhD committee at Duke saying that I thought I would be ready to defend my dissertation in May. The unflappable engineering professor, Aarne Vesilind, said he agreed, but year was I talking about?

Vigorous criticism of new ideas is a commonplace in science. While the style of the critique may vary with the character of the critic, overly polite criticism benefits neither the proponents of new ideas nor the scientific enterprise. Any substantive objection is permissible and encouraged; the only exception being that ad hominem attacks on the personality or motives of the author are excluded. It does not matter what reason the proponent has for advancing his ideas or what prompts his opponents to criticize them: all that matters is whether the ideas are right or wrong, promising or retrogressive.

Vigorous criticism is more constructive in science than in some other areas of human endeavor because in science there are adequate standards of validity that can be agreed upon by competent practitioners the world over. The objective of such criticism is not to suppress but rather to encourage the advance of new ideas: those that survive a firm skeptical scrutiny have a fighting chance of being right, or at least useful.

I am often asked what it is like to be a scientist and how one goes about being a scientist. I find such questions uncomfortable because I know of no nicely potted answers to them. It is necessary to dig deep into one’s own experience to produce anything like a worthwhile assessment. And this is to risk the perils of autobiography, usually so fascinating to the narrator and so boring to the reader.

You're in the public eye. You sometimes will get criticism, and it can be tough to swallow.

The point is professionalization. Academics-in-training worry about whether they are yet, can ever be, or even want to be professional intellectuals of the kind they are changing themselves into. Second or third or fourth year graduate students have not taken binding vows. They may have second thoughts. Nor have they been finally chosen. They might flunk out. Their committee might turn their theses down. Who knows what might happen?

Examinations are formidable even to the best prepared, for the greatest fool may ask more than the wisest man can answer.

The questions of the students are often the source of new research. They often ask profound questions that I’ve thought about at times and then given up on, so to speak, for a while. It wouldn’t do me any harm to think about them again and see if I can go any further now. The students may not be able to see the thing I want to answer, or the subtleties I want to think about, but they remind me of a problem by asking questions in the neighborhood of that problem. It’s not so easy to remind yourself of these things.

The aim should be not to “forestall all dissenting voices”, but (a) to “invite meaningful debate”; (b) “to invite the scholarly challenges and ensuing debate that can lead to better insights and closer approximation of the truth”; (c) “to go beyond what can be grasped at first contact, and as a consequence of having to defend perceptions against competing views, to investigate matters more thoroughly”; (d) to “approximate truth more closely”; (d) to “go beyond initial impressions and beyond the validation of preconceived interpretations”; (e) to “embrace the scientific approach of being transparent and vulnerable – transparent by being open to verification in terms of providing supporting evidence and discussing potentially conflicting evidence, and vulnerable by being open to challenge and potential falsification“; (f) “to evaluate the very different perspectives that are current and thus to reach beyond the differences in perspective, ideology or bias” (HOCK 2005:282-3).

Let the critics ask! Their very opposition may serve as a stimulant for their own curiosity, causing them to enter into a deeper research or analysis. The truth will always prevail in spite of personal or limited opinions.

I think the weird thing about being a scientist, or an academic in general, is you have to believe really strongly in what you do, while questioning it all the time ... and that's a hard balance to have.