rous and prejudicial endeavour
to force it down at so incommodious a time, and with so much aversion,
and believe that it marvellously distempers a sick person at a time when
he has so much need of repose. And more over, if we but consider the
occasions upon which they usually ground the cause of our diseases, they
are so light and nice, that I thence conclude a very little error in the
dispensation of their drugs may do a great deal of mischief. Now, if the
mistake of a physician be so dangerous, we are in but a scurvy condition;
for it is almost impossible but he must often fall into those mistakes:
he had need of too many parts, considerations, and circumstances, rightly
to level his design: he must know the sick person's complexion, his
temperament, his humours, inclinations, actions, nay, his very thoughts
and imaginations; he must be assured of the external circumstances, of
the nature of the place, the quality of the air and season, the situation
of the planets, and their influences: he must know in the disease, the
causes, prognostics, affections, and critical days; in the drugs, the
weight, the power of working, the country, figure, age, and dispensation,
and he must know how rightly to proportion and mix them together, to
beget a just and perfect symmetry; wherein if there be the least error,
if amongst so many springs there be but any one out of order, 'tis enough
to destroy us. God knows with how great difficulty most of these things
are to be understood: for (for example) how shall the physician find out
the true sign of the disease, every disease being capable of an infinite
number of indications? How many doubts and controversies have they
amongst themselves upon the interpretation of urines? otherwise, whence
should the continual debates we see amongst them about the knowledge of
the disease proceed? how could we excuse the error they so oft fall into,
of taking fox for marten? In the diseases I have had, though there were
ever so little difficulty in the case, I never found three of one
opinion: which I instance, because I love to introduce examples wherein I
am myself concerned.

A gentleman at Paris was lately cut for the stone by order of the
physicians, in whose bladder, being accordingly so cut, there was found
no more stone than in the palm of his hand; and in the same place a
bishop, who was my particular friend, having been earnestly pressed by
the majority of the physicians whom he consulte