@proofreadmyessay,
I would find situations without direct cause or reason if you don't like to say because... If one event only follows from another, then you can say: Then... For example: If you know your dog will crap on the rug if not let out before you go to work, then you better let him out to do his business... Or you can say: You let your dog out to do his dumpling because if you forget he will make his mess on your floor... Therefore is of the same order, meaning for that reason, as in: The dog was not let out, therefore the smell of crap was your welcome home...
It is nice from the point of view of aesthetics to avoid too much of repetition in prose... To talk rationally about events we must often assign a cause to them and not simply report them as without cause... To understand human behavior which is the real problem, we must see that so much of what people actual do springs from their character and not from any defined cause... For example: When people kill people it is usually in hot blood rather than in cold blood, and they can offer an excuse but never a rational cause to justify their action...A very troubling aspect of modern life is the serial killer who is primarily a killer or strangers... As one killer who was caught only because he talked to the one who turned him in said: It had no motive... It may have been the reason it held the attraction for him that it did, that there was no cause for it...
Science and nature have reasons we presume for all that happens, but people in their use of science and abuse of nature think they have risen above the need for reason and living well considered lives... It is madness to be sane, and sane to be mad... Literally, everyone is touched in some fashion by neurosis... We are all pathetic; but not all of us are pathological...