Can the law of nature be changed?
It seems that the law of nature can
The Gloss on Ecclesiasticus 17:9 (“He gave them instructions,
and the law of life”) says, “He wished law of the letter
to be written in order to correct the natural law.”
But what is corrected is changed. Therefore, the
natural law can be changed.
The killing of the innocent is contrary to the natural
law, as are adultery and theft as well. But these have
been changed by God, viz., (a) when God commanded Abraham
to kill his innocent son, according to Genesis 22:2; (b)
when He commanded the Jews to steal the vases they had
borrowed from the Egyptians, according to Exodus 12:35;
and (c) when He commanded Hosea to take a prostitute as
his wife, according to Hosea 1:2. Therefore, the natural
law can be changed.
In Etymologia Isidore says, “The communal
possession of all things and equal liberty belong to
natural law.” But we see that these have been changed
through human laws. Therefore, it seems that the natural
law is changeable.
But contrary to this:
Decretals, dist. 5, says, “The natural law derives
from the very beginnings of the rational creature.
Neither does it change over time, but remains immutable.”
There are two ways to understand what it is for the
natural law to be changed.
First, it is changed by something’s being added to it.
In this sense nothing prevents the natural law from
being changed. For many things useful to human
life have been added to the natural law, both by the
divine law and also by human laws.
the natural law might be thought of as being changed
by way of subtraction—so that, namely, something that
was previously in accord with the natural law ceases
to belong to the natural law. Given this sense
of change, the law of nature is altogether unchangeable
with respect to its first principles. Now with
respect to its secondary precepts, which we have claimed
to be, as it were, particular conclusions in the neighborhood
of the first principles, the natural law is not changed
so as to prevent its always being the case that what
the natural says is right in the preponderance of particular
cases. However, in a few cases, as was explained
above (a. 4), it can be changed in some particular
because of special causes that obstruct the observance
of secondary precepts.
Reply to objection 1:
The written law is said to have been given in order to
correct the law of nature either because (a) what the
natural law is lacking was supplied by the written law, or
because (b) the law of nature had in certain respects been
corrupted in the hearts of some to such an extent that
they took what was naturally bad to be good, and this sort
of corruption needed correction.
Reply to objection 2:
Everyone in general, both the innocent and the guilty,
dies by natural death, and according to 1 Kings 2:6
(“The Lord gives death and gives life”), natural death
is imposed by God’s power because of Original Sin.
And so by God’s command death can be inflicted without
any injustice on any man, whether guilty or innocent.
Similarly, adultery is sexual intercourse with someone
else’s wife, who was sworn to that other man by a divinely
given law. Hence, for someone to be intimate with
any woman by God’s command is neither adultery nor fornication.
The same holds for theft, which is the taking of what
belongs to another. For whatever someone takes
at the command of God, who is the owner (dominus)
of the universe, is such that he is not taking it against
the owner’s will—which is what theft is.
not only is it the case that whatever is commanded by
God in human affairs is by that very fact just, but
also, as was explained in the First Part (ST
1, q. 105, a. 6), whatever is done by God among natural
things is in some sense natural.
Reply to objection 3:
There are two ways in which something is said to belong
to the natural law (esse de iure naturali).
First, something is said to belong to the natural law
because nature inclines one toward it, e.g., that one
should not harm another.
Second, something is said to belong to the natural law
because nature has not induced the contrary. For
instance, we could say that it belongs to the natural
law that man is unclothed, since nature does not give
him clothes, but instead human art invented them.
is in the second sense that a communal possession of
all goods and equal liberty for all are said to belong
to the natural law—since, namely, servitude and the
distinctions among possessions are induced not by nature
but by men’s reason because of their usefulness to human
life. And so on this score the law of nature has
not been changed except by addition.