Great Throughts Treasury

A database of quotes

William Harvey

English Physician, first to describe and detail blood circulatory system

"There is no perfect knowledge which can be entitled ours, that is innate; none but what has been obtained from experience, or derived in some way from our senses; all knowledge, at all events, is examined by these, approved by them, and finally presents itself to us firmly grounded upon some preexisting knowledge which we possessed: because without memory there is no experience, which is nothing else than reiterated memory; in like manner memory cannot exist without endurance of the things perceived, and the thing perceived cannot remain where it has never been."

"Every affection of the mind that is attended with either pain or pleasure, hope or fear, is the cause of an agitation whose influence extends to the heart, and there induces change from the natural constitution, in the temperature, the pulse and the rest, which impairing all nutrition in its source and abating the powers at large, it is no wonder that various forms of incurable disease in the extremities and in the trunk are the consequence, inasmuch as in such circumstances the whole body labors under the effects of vitiated nutrition and want of native heat."

"All we know is still infinitely less than all that remains unknown."

"And so I conclude that blood lives and is nourished of itself and in no way depends on any other part of the body as being prior to it or more excellent... So that from this we may perceive the causes not only of life in general... but also of longer or shorter life, of sleeping and waking, of skill, of strength and so forth."

"Doctrine once sown strikes deep its root, and respect for antiquity influences all men."

"Even if this may take more than half an hour or an hour or a day for its accomplishment, it does nevertheless show that the beat of the heart is continuously driving through that organ more blood than the ingested food can supply, or all the veins together at any time contain."

"Everyone admits that the male is the primary efficient cause in generation, as being that in whom the species or form resides, and they further assert that his genitures emitted in coitus causes the egg both to exist and to be fertile. But how the semen of the cock produces the chick from the egg, neither the philosophers nor the physicians of yesterday or today have satisfactorily explained, or solved the problem formulated by Aristotle."

"I avow myself the partisan of truth alone."

"I just start singing, and it all comes back."

"I profess to learn and to teach anatomy not from books but from dissections, not from the tenets of Philosophers but from the fabric of Nature."

"I want a full and thorough investigation of this, and then we will issue the report publicly, ... We want to be transparent about this, and we are cooperating fully with the NCAA."

"In attempting to discover how much blood passes from the veins into the arteries I made dissections of living animals, opened up arteries in them, and carried out various other investigations. I also considered the symmetry and size of the ventricles of the heart and of the vessels which enter and leave them (since Nature, who does nothing purposelessly, would not purposelessly have given these vessels such relatively large size). I also recalled the elegant and carefully contrived valves and fibres and other structural artistry of the heart; and many other points. I considered rather often and with care all this evidence, and took correspondingly long trying to assess how much blood was transmitted and in how short a time. I also noted that the juice of the ingested food could not supply this amount without our having the veins, on the one hand, completely emptied and the arteries, on the other hand, brought to bursting through excessive inthrust of blood, unless the blood somehow flowed back again from the arteries into the veins and returned to the right ventricle of the heart. In consequence, I began privately to consider that it had a movement, as it were, in a circle."

"In man, then, let us take the amount that is extruded by the individual beats, and that cannot return into the heart because of the barrier set in its way by the valves, as half an ounce, or three drachms, or at least one drachm. In half an hour the heart makes over a thousand beats; indeed, in some individuals, and on occasion, two, three, or four thousand. If you multiply the drachms per beat by the number of beats you will see that in half an hour either a thousand times three drachms or times two drachms, or five hundred ounces, or other such proportionate quantity of blood has been passed through the heart into the arteries, that is, in all cases blood in greater amount than can be found in the whole of the body. Similarly in the sheep or the dog. Let us take it that one scruple passes in a single contraction of the heart; then in half an hour a thousand scruples, or three and a half pounds of blood, do so. In a body of this size, as I have found in the sheep, there is often not more than four pounds of blood."

"In the above sort of way, by calculating the amount of blood transmitted [at each heart beat] and by making a count of the beats, let us convince ourselves that the whole amount of the blood mass goes through the heart from the veins to the arteries and similarly makes the pulmonary transit."

"It helps us to maintain one of the things we are proud of -- reserves... Regardless of how many hurricanes hit us, and we were hit with several last year, we have managed to maintain our reserves. I think one of the things a city has to do is to maintain itself, not only operate in the black daily, but (remain) in the black when you hit your reserves."

"It is, however, an argument of no weight to say that natural bodies are first generated or compounded out of those things into which they are at the last broken down or dissolved."

"Memory cannot exist without endurance of the things perceived, and the thing perceived cannot remain where it has never been."

"Moderate labor of the body conduces to the preservation of health, and cures many initial diseases."

"Nature is nowhere accustomed more openly to display her secret mysteries than in cases where she shows tracings of her workings apart from the beaten paths; nor is there any better way to advance the proper practice of medicine than to give our minds to the discovery of the usual law of nature, by careful investigation of cases of rarer forms of disease."

"Our total consolidated earnings were obviously battered by the charges related to our Brazil investments. However, we continue making good progress in streamlining our business portfolio."

"Restlessness and intermission from sleep grieved persons are molested with, whereby the blood is dried."

"Take a walk to refresh yourself with the open air, which inspired fresh doth exceedingly recreate the lungs, heart, and vital spirits."

"The animal's heart is the basis of its life, its chief member, the sun of its microcosm; on the heart all its activity depends, from the heart all its liveliness and strength arise. Equally is the king the basis of his kingdoms, the sun of his microcosm, the heart of the state; from him all power arises and all grace stems."

"The challenge prior to the court decision was deciding exactly what methods and approaches they could use ... Educating All of One Nation."

"The heart is the household divinity which, discharging its function, nourishes, cherishes, quickens the whole body, and is indeed the foundation of life, the source of all action."

"The examination of the bodies of animals has always been my delight; and I have thought that we might thence not only obtain an insight into the . . . mysteries of Nature, but there perceive a kind of image or reflex of the omnipotent Creator himself."

"The heart of animals is the foundation of their life, the sovereign of everything within them, the sun of their microcosm, that upon which all growth depends, from which all power proceeds."

"There is a lust in man no charm can tame: Of loudly publishing his neighbor's shame: On eagles wings immortal scandals fly, while virtuous actions are born and die."

"This organ deserves to be styled the starting point of life and the sun of our microcosm just as much as the sun deserves to be styled the heart of the world. For it is by the heart's vigorous beat that the blood is moved, perfected, activated, and protected from injury and coagulation. The heart is the tutelary deity of the body, the basis of life, the source of all things, carrying out its function of nourishing, warming, and activating body as a whole. But we shall more fittingly speak of these matters when we consider the final cause of this kind of movement."

"Toil of the mind destroys health by attracting the spirits from their task of concoction to the brain; whither they carry along with them clouds of vapours and excrementitious humours."

"Very many maintain that all we know is still infinitely less than all that still remains unknown."

"We try to run a clean program, so we consider any violation \'serious' if it's proven to be true, ... But right now, these are just allegations. The committee will meet with the NCAA to determine the number of possible violations and their nature."

"What amaritude or acrimony is deprehended in choler, it acquires from a commixture of melancholy, or external malign bodies."

"When in many dissections, carried out as opportunity offered upon living animals, I first addressed my mind to seeing how I could discover the function and offices of the heart's movement in animals through the use of my own eyes instead of through the books and writings of others, I kept finding the matter so truly hard and beset with difficulties that I all but thought, with Fracastoro, that the heart's movement had been understood by God alone."