By 1784, and perhaps as early as 1777, the very influential Scottish physician William Cullen in his First Lines of the Practice of Physick was praising the waistcoat not only as a means of restraint, but also as a remedy and even suggesting a physiological rationale for its benefit. This passage is so striking that it is worth quoting at length.
"Restraining the anger and violence of madmen is always necessary for preventing their hurting themselves or others: but this restraint is also to be considered as a remedy. Angry passions are always rendered more violent by the indulgence of the impetuous motions they produce; and even in madmen, the feeling of restraint will sometimes prevent the efforts which their passion would otherwise occasion. Restraint, therefore, is useful, and ought to be complete; but it should be executed in the easiest manner possible for the patient, and the strait waistcoat answers every purpose better than any other that has been yet thought of. The restraining madmen by force of other men as occasioning a constant struggle and violent agitation is often hurtful. although there may be no symptoms of any preternatural fulness or increased impetus of blood in the vessels of the brain, a horizontal posture always increases the fulness and tension of these vessels, and may thereby increase the excitement of the brain."
Philippe Pinel may have learned about the strait waist coat from Cullen when he translated this passage in 1785, incidentally using the term chemisette serrèe, suggesting that he was not yet familiar with the commonly used term camisole de force. In his Treatise on Insanity in 1800, Pinel argued that his use of the camisole de force was evidence that he subscribe to the same philanthropic principles as those of the York Retreat:
We are doubtless without the advantages of Dr. [Thomas] Fowler's establishment in Scotland [actually the Retreat in York] with its expansive grounds and fine accommodations. But I can attest after two years of diligent observation that the same principles of philanthropy prevail in the management of the insane at Bicêtre. The attendants, under no pretext whatever, ever raise a hand, even in reprisal. Strait jackets [Gilets de force] and seclusion, for short periods, are the only punishments inflicted. When kind treatment or the imposing trappings of repression fail, a clever ploy sometimes produces unexpected cures [TAM. 1800, 65-6].