Is there really such a thing as natural law?


Like most people I struggle with Catholic moral teaching. In theory it all sounds great, but in practice it seems like something only a non-corporeal being would come up with. My question is: how do I know that natural law is objectively true and not just something someone made up? In the following arguments I attempt to show the absurdity of natural law arguments.

  1. God commanded us (everyone) to “be fruitful and multiply”. If you can have children but you purposely avoid marriage and sex then that is against God’s will. Life-long celibacy is clearly not what God intended, He gave us genitals because He expects us to use them.

  2. Flying in airplanes is immoral because obviously God never intended human beings to fly. Just because we’ve found a way to fly doesn’t mean that we should. Just because I can take a pill and enjoy the sexual act without concern for getting pregnant doesn’t mean I should. The sexual act has a purpose which is procreation. Feet have a purpose, which is to stand and to walk. God intends for us to walk, not fly. The desire to fly is a form of angelism, wanting to fly like an angel when God has intended for us to be human and to accept our humaness–earth-bound as it is.

  3. We can be certain that God intended human beings to be nudists because we aren’t born wearing clothes. Adam and Eve were originally naked. It was only after they sinned that they started wearing clothes. God never told us to wear clothes. God doesn’t want us to be ashamed of our naked bodies—if we are truly free of sin then we would be nudists.


I do not see why we should be bound with our limitations; it is an intrinsic human desire to manumit ourselves from them. Your example of fight is excellent, Tormentd-san.


My question is: how do I know that natural law is objectively true and not just something someone made up?

the natural law protects and recognizes dignity of man. it is therefore a moral law. anytime we go against the natural law we go against the law written in our hearts. “The natural law is nothing other than the light of understanding placed in us by God; through it we know what we must do and what we must avoid. God has given this light or law at the creation”.

the natural law “hinges upon the desire for God and submission to him, who is the source and judge of all that is good, as well as upon the sense that the other is one’s equal.

we know that we do not bring ourselves into this world. it is only by love that we are able to live. therefore it is entirely insane to believe that there is no right or wrong because to think so goes against our very existance and being itself.

flying planes or driving cars or spaceships in of itself has nothing to do with the dignity of man. to kill someone or objectifying them through pornography or fornication does.


I suggest you obtain the book 50 Questions on the Natural Law: What It Is and Why We Need It by Charles Rice.

None of the three examples you give have their root in natural law. You are not understanding what natural law is.

(1) Be frutiful and multiply is a divine command, not part of the natural law. Natural law does tell us what our generative organs are for-- and each time we use them we must do so in accordance with the natural law-- however, natural law does not compel us to use our generative organs.

(2) The “natural” in natural law is not the opposite of “man made”. Your flying example is not relevant to natural law.

(3) Again, a misunderstanding of what natural law means.


Hi Tormentd,

What we call natural law is the rules of morality that humans are able to recognize without the help of revelation (bible etc.)

A good knife is a knife that cuts. A bad knife is a knife that does not. This means that we determine goodness by the purpose of a thing. The purpose of a knife is to cut. So we judge its goodness or badness by that.

The same applies to human actions. The purpose of food is to sustain life. If you use it to gorge yourself beyond the needs of nutrition, you go against the purpose of food, and commit an act that is not good.

The primary purpose of sex is procreation. If you wilfully thwart this purpose, you commit an act that is not good.

So morality is determined by purpose. That is the natural law. Ultimately it goes back to God, who made all things and determined their purpose.



I’d say yes because regardless of where you go every society has some sort of rules that it functions under whether they are Christian, Muslim, Communist, or back-of-nowhere jungle people who worship a stump in the ground.

I believe that that indicates that mankind has some innate sense of right and wrong that develops from somewhere. The societal mores are an extension of and response to the individual human natural law within them.


People often confuse natural law with the laws of nature. Its an easy misunderstanding. The laws of nature usually have a basis in science, whereas the natural law has its basis in what it means to be human from a philosophical/theological viewpoint.


thanks for your help everyone. I think I understand better now and will try to find the book that was mentioned. I’m glad there is a place I can come with all of my tormented thoughts and find thoughtful helpful answers.


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