After practicing medicine for several years, I got infected by the research virus, and eventually decided that I wanted to be a scientist more than I wanted to be a physician. A short experience in basic science research has convinced me that neither rats nor labs were a good match for me—so I switched to epidemiology.
It did not take very long before I realized that epidemiological research was loaded with conundrums and controversies. Some were disguised as "statistics"; others as "epistemology" (not to be confused with "epidemiology"...) Since then I have tried to study, understand, and teach the trail along which we study a cause-and-effect relation: a trail that begins with philosophy of science (what is scientific knowledge?), continues through causal diagrams, two models of causation, study design, and sources of bias, and ends with computation (statistical models). I have unlimited respect for inquisitive minds, clear thinking, and good, non-pretentious, writing.
My subject matter science has included cardiovascular diseases and disordered breathing during sleep, but I can find interest in thinking about any causal question. In recent years, I have also been working on the methodology of causal diagrams (directed acyclic graphs), especially in the context of information bias, thought bias (newly described), colliding bias, and effect-modification bias. My collaborator on these topics has been my son, Doron Shahar, who is now a PhD student (math) at the University of Arizona.
Our work on the taxonomy of biases was summarized in 2012 [PDF].
Revised thoughts (2014) on effect modification and partial effects can be found here [PDF].
"In today's scientific world, the cards are stacked heavily against true
scientific breakthroughs. All too often, scientific truth is determined by
the authority of experts and textbooks, not by logic and reason." --Anonymous
"There is nothing particularly scientific about excessive caution.
Science thrives on daring generalizations." -- L. Hogben
"A first principle not formally recognized by scientific methodologists:
when you run into something interesting, drop everything else and study
it." -- B.F. Skinner
"Science today is locked into paradigms. Every avenue is blocked by
beliefs that are wrong, and if you try to get anything published by a
journal today, you will run against a paradigm and the editors will
turn it down" --Sir Fred Hoyle
"New ideas are always criticized - not because an idea lacks merit, but
because it might turn out to be workable, which would threaten the
reputations of many people whose opinions conflict with it." -- Physicist (anonymous)
"All truth passes through three stages: First, it is ridiculed; Second,
it is violently opposed; and Third, it is accepted as self-evident."
-- Arthur Schopenhauer
"A tribute to a scientist is a modern version of idolatry." --Anonymous
"If you restrict the journal to publishing only what pleases the
referees, you end up publishing what is popular, and while it does make
everyone feel more comfortable, you are guaranteed to miss the
occasional breakthrough." -- A. Dessler
"A new scientific truth does not triumph by convincing its opponents and
making them see the light, but rather because its opponents eventually
die and a new generation grows up that is familiar with it." -- M. Planck
"A great many people think they are thinking when they are merely
rearranging their prejudices." -- William James
"The fact that an opinion has been widely held is no evidence whatever
that it is not utterly absurd; indeed in view of the silliness of the
majority of mankind, a widespread belief is more likely to be foolish
than sensible." -- Bertrand Russell
"The great tragedy of science is the slaying of a beautiful hypothesis by an ugly fact" --Thomas Huxley
"The most beautiful thing in science is the slaying of a tyrant theory by an oppressed fact.
But even when slayed, no theory ever dies." --Doron Shahar
"Censorship in science shows up in many forms: ignoring, belittling, misinterpreting, intimidating,
throwing mud, finding excuses, prioritizing, marginalizing, silencing. Of course—all in the name of science."