LIV. There now only remains within the compass of the predicamental
scale, one other thing to consider, which is the highest, and most
sublime within the reach of physics, and that is, the nature and
composition of the body; but where will this lead us to, the point being
equally doubtful with all the rest? The composition of the body, is
divided into elemental and mixed; but as this last is composed of the
other, unless we know what the elemental is, it is impossible to know
of what the mixture consists. Very well; but who knows the nature and
number of the elements? To this question, methinks I hear four answers,
from four sects of philosophers, which are all different, although each
pretends to exclude the others from a competent knowledge of the matter.
The Aristotelites say, that they are air, fire, earth, and water. The
chymists, that they are salt, sulphur, mercury, earth, and water. The
Cartesians insist, that they are composed of the subtil, the globulous,
and another matter which is more gross, and which they call the third
element; and the atomists, that they consist of the atoms. These are
the opinions, which are at present the most prevailing, although there
are numbers of others which I shall omit to mention, because they have
but few votaries. Now which of these opinions is the true one? Perhaps
neither. At least there is but one sect out of the four that admits
either of them to be true, and whichever that sect adheres to, the other
three assert to be false; which amounts to the same, as saying that
one witness deposes to the truth of the matter in question, and that
three give testimony against it. Thus no judge to whom the decision is
confided, can give sentence in favour of either of the parties; it being
out of his power to affirm, that any one of their systems is right and
true.
LV. As the audience before whom I propound this reflection, is composed
chiefly of the followers of Aristotle, methinks I hear them exclaim,
that if we were to collect the suffrages of the academic professors,
we should find most votes in favour of his opinion. To this, I reply
in the first place, that although a plurality of sectaries, gives
greater extrinsic probability to an opinion, still it does not afford
certainty, nor intrinsic probability; and the question here, is not
whether Aristotle’s opinion is the most probable, but whether it is
certain. I reply secondly, that it is doubtful, if we were to include
the professors who teach physics in all nations, whether we should in
reality find a majority of votes in favour of Aristotle; and unless
we could prove by some authentic instrument, that God has limited the
knowledge of philosophy to our nation only, and has excluded all others
from inheriting the science, I do not know upon what pretension we can
ground a right, of admitting none but Spaniards to vote in the question.
Some of our antient professors say, that we should not regard the
opinions of strangers, because they are novelists; but at the same time,
strangers reply, that we should take no account of what the Spaniards
assert, because they are obstinate and wrong-headed, and that there is
no proof, be it ever so clear, that will make them depart from their old
opinions; to which they add, that in Spain, they do not follow Aristotle
from choice, but from necessity; for that it requires an heroic spirit,
to contradict any thing that has been advanced by Aristotle in that
kingdom, where whoever dares venture to oppose him, is instantly assailed
by tempests of injuries, which fall on his head like violent hail storms.
Nor is even an heroic spirit, sufficient to enable a man to support such
an opposition, because the duty of obedience, obliges people not to
depart from the line of their school; and this is also frequently the
case, in other countries; and from hence, some Anti-Aristotelites have
insisted, that the plurality of votes in favour of Aristotle should not
prevail, because they cannot be supposed to be free.
LVI. But abstracted from the quantum of extrinsic probability, contained
in the doctrine of Aristotle respecting the elements; I assert, that
upon a strict examination, you will not find more truth contained in
his sentiments, than in those of his adversaries. This opinion, I
deduce from the position, that his first qualities consist of four,
to wit, heat, cold, wet, and dry, from which in exact proportion, he
attributes one to be impregnated in the highest degree with each element,
and another near to the highest. This proof, goes lame in innumerable
particulars. First, the giving to these qualities the title of first,
is conferring a mere voluntary dignity on them, and especially, when
we know the invincible difficulty, that attends establishing, that all
the others result from them. Secondly, it is very doubtful, whether all
the four beforementioned, can properly be called qualities; for many
Aristotelites, and with great colour of reason, deny humidity and dryness
to be such. That which is humid, is not so from any quality it possesses
in itself, but because it has imbibed into its pores some foreign liquid
substance, and let that be evaporated, and it will remain dry; from
which we may conclude, that humidity is a substance, and that dryness
consists in the want of that substance. Thirdly, the appropriating these
as two of the four elements, is done without any foundation or reason.
In the next place, how can they prove that water is cold in the highest
degree? If this was true it would kill us; neither can they prove it so,
in a more moderate, or secondary degree, for we are taught by experience,
it is indifferent to both cold and heat, according to the agent that is
applied to it. It is heated by the fire; and remove it from the fire,
and it becomes cool again, not because it has any propensity or natural
disposition to be cold, but because it is made so, by the cool atmosphere
which surrounds it. There are many other very grave objections to be
urged against this doctrine of the four qualities; and therefore the
foundation upon which it is built, and the reasoning deduced from it to
establish the quaternian system of the elements, are both very slight and
futil.
LVII. The second argument, is built on the correspondence of the four
humours of the body, with the four Aristotelic elements; that is to say,
the blood with the air, the choler with the fire, the melancholy with the
earth, and the pituitous with the water. But this puts us in a worse
situation than we were before. In the first place, it is a doubt among
the medical people, whether the humours of our bodies consist precisely
of four. Some say they are more, and others that they are less. Some add
to the four, the lymph, the pancreatic juice, and the nervous fluid;
and some again will not admit, that there is any other humour except
the blood. Secondly, if the four elements correspond only with the four
humours, we are left without an element to correspond with the solids,
which on account of the hardness of their substance, might with more
propriety be compared to the earth, than to the melancholy humour, which
is beyond comparison less hard and solid than the other. Thirdly, in the
same voluntary manner, with which they assign four elements to correspond
with the four humours, they may assign one element to correspond with the
flesh, another with the bones, another with the marrow, another with the
fat, or adipose substance, another with the tendons, and so on. Fourthly,
in order to reason justly upon the human body, or animal species, we
should not seek for four substances that are analogous to the four
humours, but for four that enter into all the mixtures; for the question,
relates to elements that partake of the composition of all mixtures in
general, and not precisely of the animal. But what traces can we discern,
of four humours, or four substances, equivalent to these, either in
minerals, or plants?
LVIII. The third argument in support of this quaternian system, is
pretended to be derived from experience; for it is alledged, that when
a piece of wood is burning, we see it resolve itself into the four
Aristotelic elements. At first it emits a small portion of water; then
it takes fire; the fire is followed by smoke, which we know to be of an
aerial nature, by its ascending to the airy region; and last of all,
there remains a portion of earth in the ashes.
LIX. Although as Etmuller says, in matters of physics and medicine,
_præstat unum experimentum centum rationibus_, still, the experiment
just alledged is so defective, that it is not of more value than the
arguments before urged. In the first place, dry wood, may as properly
be called a mixture as green wood, notwithstanding which, it emits no
water upon being laid on the fire. Secondly, as we are here treating
of the elements in general which enter into, and make a part of the
composition of every species of mixture, the fire should produce the
same appearances, and have the same effect upon them, that it has upon
the wood; but this does not happen, for minerals laid on the fire emit
no water, unless it is when they have imbibed some foreign moisture.
Thirdly, the chymists by means of fire differently applied, extract from
wood and other mixtures, various substances, which differ from those
four that are produced from the wood in the ordinary way of burning it;
and it seems reasonable from hence, that we should augment the number
of the elements. Fourthly, we do not know whether these substances
pre-existed in the wood, or whether they were produced _de novo_ by the
fire. Fifthly, the ash is not earth, nor an elemental or simple body
as is supposed, for there may be separated from it a large portion of
salt, which is a distinct substance from either of the four; for it is
neither earth, air, water, or fire. Sixthly, neither is the smoke air,
as is manifest from the soot which condenses in the chimney. If I should
be told, that in the smoke is contained a variety of particles, some of
which compose the soot, which remains in the chimney, and others which
mount higher, and are impregnated with the atmosphere, and become air; I
reply, that in consequence of this, they should admit of a fifth element
of soot; or to speak more properly, of five or six additional elements;
for Mr. Boyle informs us, that the chymists can extract from soot, five
or six different substances. Finally, all that becomes ashes, existed
before in the form of fire; from whence it follows, that the form of
ashes is a new production, for matter cannot exist under two substantial
forms at one and the same time; and consequently, the elemental form of
earth which the Aristotelites ascribe to the ashes, could not pre-exist
in the mixture, but must be a new production. This objection militates
principally against the Aristotelic principles; but others might be
formed in different shapes, against every system whatever.
LX. I have combated only the Aristotelic opinion of the elements, not
because the others are not incumbered with equal difficulties, and
exposed to equal objections, but because in Spain, we suppose the others
to be perplexing, and even improbable, and conclude that of the four
elements, to be just and right; I therefore chose to attack this system,
to let my countrymen see, that we know nothing with certainty respecting
the elements.