Putting nature on the rack

What was it that distinguished the modern scientific method inaugurated by Bacon, Galileo, Descartes, and Co. from the science of the medievals?  One common answer is that the moderns required empirical evidence, whereas the medievals contented themselves with appeals to the authority of Aristotle.  The famous story about Galileo’s Scholastic critics’ refusing to look through his telescope is supposed to illustrate this difference in attitudes.

The problem with this answer, of course, is that it is false.  For one thing, the telescope story is (like so many other things everyone “knows” about the Scholastics and about the Galileo affair) a legend.  For another, part of the reason Galileo’s position was resisted was precisely because there were a number of respects in which it appeared to conflict with the empirical evidence.  (For example, the Copernican theory predicted that Venus should sometimes appear six times larger than it does at other times, but at first the empirical evidence seemed not to confirm this, until telescopes were developed which could detect the difference; the predicted stellar parallax did not receive empirical confirmation for a long time; and so forth.)

 
Then there is the fact that the medievals were simply by no means hostile to the idea that empirical evidence is the foundation of knowledge; on the contrary, it was a standard Scholastic slogan that “there is nothing in the intellect that was not first in the senses.”  Indeed, Bacon regarded his Scholastic predecessors as if anything too quick to believe the evidence of the senses.  The first of the “Idols of the Mind” that he famously critiques, namely the “Idols of the Tribe,” included a tendency to take the deliverances of sensory experience for granted.  The senses could, in Bacon’s view, too readily be deceived, and needed to be corrected by carefully controlling the conditions of observation and developing scientific instruments.  And in general, the early moderns regarded much of what the senses tell us about the natural world -- such as what they tell us about secondary qualities like color and temperature -- to be false. 

So, it is simply not the case that the difference between the medievals and the early moderns was that the latter were more inclined to trust empirical evidence.  On the contrary, there is a sense in which that is precisely the reverse of the truth. 

Where empirical evidence is concerned, the real difference might, to oversimplify, be put as follows.  Both the medievals and the early moderns regarded sensory experience as a crucial witness to the truth about the natural world.  But whereas the medievals regarded it as a more or less friendly witness, the moderns regarded it as a more or less hostile witness.  You can, from both sorts of witness, derive the truth.  But the methods will be different.

Hence, a friendly witness can more or less be asked directly for the information you want.  That doesn’t mean he might not sometimes need to be prodded to answer.  Even if he is honest, he might be shy, or reluctant to divulge something embarrassing, or just not very articulate.  It also doesn’t mean that everything he says can be taken at face value.  He may be forgetful, or confused, or just mistaken now and again.  A hostile witness, by contrast, though he has the information you want, cannot with confidence be asked directly.  Even if he is articulate, has a crystal clear memory, etc., he may simply refuse to answer, or may persistently beat around the bush, or may flat-out lie, seriously and repeatedly.  Thus, he may have to be tricked into giving you the information you want, like the Jack Nicholson character in A Few Good Men.  Or you may be tempted to threaten or beat it out of him, like one of the cops in L.A. Confidential would.  So, you might say that whereas the medieval Aristotelian scientist has a conversation with nature, the early modern Baconian scientist waterboards nature.  Hence the notorious Baconian talk about putting nature to the rack, torturing her for her secrets, etc. 

Of course, this is melodramatic.  And to be fair, Bacon himself seems not to have put things quite the way commonly attributed to him (i.e. the stuff about torture and the rack).  All the same, the medievals and moderns do disagree about the degree to which the world of ordinary experience and the world that science reveals -- what Wilfrid Sellars called “the manifest image” and “the scientific image” -- correspond.  For the Aristotelian, philosophy and science are largely in harmony with common sense and ordinary experience.  To be sure, they get at much deeper levels of reality, and they correct common sense and ordinary experience around the edges, but they don’t overthrow common sense and ordinary experience wholesale.  For the moderns, by contrast, philosophy and science are likely radically to conflict with common sense and ordinary experience, and may indeed end up overthrowing them wholesale. 

(This is not a difference concerning whether to accept the results of modern science, by the way.  It is a difference about how to interpret those results.  For example, it is a difference over whether to regard modern science as giving us a correct but merely partial description of nature -- a description which needs to be supplemented by and embedded within an Aristotelian metaphysics and philosophy of nature -- or whether to regard modern science instead as an exhaustive description of nature, and a complete metaphysics in its own right.)

The early moderns’ attitude of treating nature as a hostile witness -- of thinking that the truth about nature is largely contrary to what ordinary experience would indicate -- is one of the sources of the modern tendency to suppose that “things are never what they seem,” that traditional ideas are typically mere prejudices, that authorities and official stories of every kind need to be “unmasked,” and so forth.  Michael Levin has called this the “skim milk fallacy,” and I’ve often noted some of its social and moral consequences (e.g. here, here and here).  But these are merely byproducts of a much deeper metaphysical and epistemological revolution.