occurs, the physician ought to invent something, which though perhaps it does not always answer, yet most commonly may: and he shall draw his new method, not from the occult things (for they are dubious and uncertain) but from those, that can be fully known, that is, from the evident causes. For it makes a considerable difference, whether the distemper was occasioned by fatigue, or thirst, or cold, or heat, or watching, or hunger; or whether it arose from too much food and wine, or excess of venery. And he ought not to be ignorant of the constitution of his patient, whether his body be too moist, or too dry: whether his nerves(12) be strong or weak; whether he be frequently or seldom ailing; and whether his illnesses are severe or slight, of long continuance or short; what way of life he has pursued, laborious or sedentary, luxurious or frugal; for from these, and such like circumstances, he must often draw a new method of cure. Nevertheless even these things ought not to be so passed over, as if they were uncontroverted; for Erasistratus has affirmed, that distempers were not occasioned by them, because other people, and even the same person at different times, would not fall into a fever upon them. And some of the Methodists of our own age, from the authority of Themison (as they would have it thought) assert, that the knowledge of no cause whatever bears the least relation to the method of cure; and that it is sufficient to observe some general symptoms of distempers; and that there are three kinds of diseases, one bound, another loose(13), and the third a mixture of these. For that sometimes the excretions of sick people are too small, sometimes too large; and sometimes one particular excretion is deficient, while another is excessive. That these kinds of distempers are sometimes acute, and sometimes chronic; sometimes increasing, sometimes at a stand(14), and sometimes abating. As soon then as it is known, to which of these classes a distemper belongs if the body be bound, it must be opened; if it labours under a flux, it must be restrained; if the distemper be complicated, then the most urgent malady must be first opposed. And that one kind of treatment is required in acute, another in inveterate distempers; another, when diseases are increasing; another, when at a stand; and another, when inclining to health. That the observation of these things constitutes the art of medicine, which they define as a certain way of proceeding, which the Greeks call _Method_[AD], and affirm it to be employed in considering those things, that are in common to the same distempers: nor are they willing to have themselves classed either with the rationalists, or with those, who regard only experiments; for they dissent from the first sect, in that they will not allow medicine to consist in forming conjectures about the occult things; and also from the other in this, that they hold the observation of experiments to be a very small part of the art.