I just noticed, after at least 37 years of looking at this image of Saint Thomas Aquinas,

that he (or at least Bl. Fra Angelico imagined that he) parted his hair on the right, as do I

which is somewhat uncommon for men (at least in the late 20th and early 21st centuries (don’t know about the 13th)).
Coincidence?
I (and Saint Thomas) think NOT!
If you follow the link to Summa Theologiae Ia, q. 103, a. 7 ad 2, you will find Saint Thomas arguing, not that some divine plan connects me to him (and all right-hair-parters), but that there are no coincidences at all – that nothing happens by chance as though it were outside of God’s governance.

He makes two points: First, nothing at all comes about by pure chance, as though it occurs without any cause whatever. He argues that chance, indeed, implies order and causality, for what we (normally) mean in saying something happens “by chance” is that it results from two (or more) lines of causality intersecting unexpectedly, as when a farmer digging in his field discovers buried treasure. This is unexpected, but not uncaused, as the pirate who buried it, and the farmer who dug it up, both were causes pursuing their own ends. The ace you need to complete your royal flush appears “by chance,” though, of course, it is the result of the shuffle of the deck, and the cards your opponents drew or didn’t draw, before the deal came to you.
Second, Aquinas makes the point that from God’s perspective, there are no coincidences since there could not be. Nothing is unexpected for Him, since all lines of causality have their source in His creating and sustaining things in existence and in his giving to them whatever causality they have. And He knows and in some sense (permissively or perfectively) directs or governs wherever His creative power extends, which is to everything other than Himself which exists. (See the whole rest of ST Ia, 103 for details.)
But in asking “Coincidence ?” and declaring, “I think NOT,” we mean that there is, in fact, a cause and purpose connecting the common features. Which is, to a theist, of course, true as a matter of general theology; there are no coincidences with God. In this particular case, though, I was tacitly suggesting that our shared hairstyle implies wisdom and grace in common between Saint Thomas and myself, which of course, is the joke. As a matter of personal spirituality, though, we (or at least I) seldom know the particular purpose by which God’s governance brings disparate causes to coincide, though, of course he must have one (ultimately, ad maiorem Dei gloria). (I suppose the similarity in Thomas’s and my hairstyles might serve a divine purpose of prompting me to write this post, which might (improbably) conduce to some particular spiritual benefit someone derives from it.)

If you view posts by atheists and skeptics on the internet, though, it will not be long before you encounter the blithe dismissal of both points Aquinas makes about chance and coincidence. In denying arguments for a Creator, some skeptics merely assert (without evidence (despite their incessant demand for it from theists)) that the universe arose by chance (meaning causelessly), though we don’t normally use the term in that way in other contexts (as Aquinas actually argues for in this text). (I address this point more thoroughly in an argument for a Creator I make elsewhere.)

Likewise, the critic of religion is fond of dismissing miracles as mere coincidences, (though, to be sure, very many occurrences which purport to be “miraculous,” probably are chance intersections of ordinary lines of causality (though still under God’s governance)). The unclaimed change you find in a vending machine coin return, which is the exact amount you need to take the bus to the job interview, can be both a normal coincidence (different lines of causality bringing your need together with its satisfaction) and an act of God’s general providence.
Again, to a theist, there are no coincidences since she already knows that God governs all. To the atheist and skeptic, this is unimpressive; there can only be coincidences, since they already suppose that no wisdom or purpose guides disparate causes. At this general level, if either view were put forth as an argument for or against God as the cause of seemingly chance “miraculous” occurrences, each would pretty obviously be circular and question-begging.
When it comes to reports of particular, shall we say “spectacular,” miracles, though, atheist and skeptics employ this general strategy to deny there could be any supernatural cause for any occurrence, since everything must have an natural explanation, and what seems not to have one, must be mere coincidence. When one considers the details of the spectacular miracles, though, it seems to me at least, that their disbelief simply beggars belief. That is, they will claim that what seems spectacularly miraculous merely happened by chance, with no cause (certainly not a Divine one (even if that is not what chance means)). Or, they might claim that an apparent miracle is the result of an intersection of known (and possibly unknown) ordinary lines of causality. Yet, when examining the details of particular miracles (as those needed for the Catholic Church to declare a person a saint), it is extremely hard to believe (I think) that God did not cause the occurrence in question.

If one looks at the “Miracle of the Sun” at Fatima, for instance, in order to suppose that God did not intervene miraculously in the events of October 13, 1917, one would have to suppose that the rain that had been lasting for hours before the event just happened to stop at the time predicted and that the soaking mud coincidentally became dry dirt in a matter of minutes (leaving aside the spectacular visual experience of tens of thousands of people, including skeptical newspaper reporters, and of people several miles away) without any known – or even plausible – explanation for how that could have happened.

Or, consider the thousands of miracles documented with objective, scientific or medical evidence by credentialed, often secular, professionals, such as two for the canonization of St. Mother Teresa of Calcutta. To deny (or not affirm) Divine intervention, one would have to suppose that patients suffering from life-threatening conditions, suddenly, by some strange coincidence, recovered their health with all traces of their disease having disappeared, against any known – or even plausible – natural explanation.

And yet, some people do fail to assign a Divine cause to such spectacular unnatural occurrences. The hematologist, Jacalyn Duffin, who provided evidence of a miraculous healing through the intercession of Marguerite d’Youville, and who investigated the thousands of miracles linked to above, remained an atheist throughout the process (and presumably still is), simply accepting that the explanations of these events are unknown. I had a student tell me once that she was only there, in my class, because as a child she nearly died of some medical condition, and was miraculously healed due to her parents’ and family’s prayers. Apparently she had been told this all her life, and she believed the events occurred as her parents had always told her, yet she still did not believe God was real (much less the cause of her healing). I thought it remarkable she told me all of this, and held the convictions she did. Apparently, we really are free to decide what we shall believe in the face of what seems to me should be pretty compelling evidence. But then again, I have explained elsewhere how my convictions are not really dependent, or as far as I can tell, shaped by the miraculous or wonderous (other than the marvelous truth that God created everything, and sent His Son to die for my sins, so I might be happy with Him forever).
Whatever evangelical weight the miraculous should have, there are a couple of objections worth considering. For instance, a skeptic or atheist might grant that even if the details of an account of a spectacular miracle were true, it does not show that God is real, since if God did exist and intervene in such extraordinary ways, He would do so more often. I had one student even assert that, while God might perform miracles for some (whom He loved), He must hate all those who do not receive their requested miracle. That seems especially harsh: the Giver of gifts need not hate those who receive none, since no one is due any. But, it fundamentally misses the point about true miracles: if the atheist were right, and there were no God, there should not be any miracles at all. While we might like more, even one true, well-documented miracle disproves the atheist denial of God. Fewer miracles than expected, however, do not disprove God’s existence. It just shifts to the problem of evil, for which there is an answer, though it’s not completely satisfying, for it comes down to the point of Aquinas’ text from the Summa, vis., everything is under God’s governance, because it must be.
The focus on miracles, too, seems to miss a really fundamental fact about God and our relationship to Him. While only He can perform the truly, spectacularly miraculous event (like at Fatima or dramatic healings), He is not in the business of trying to impress us, or fix all our problems. The main thing about religious (or at least Catholic) faith is that God (and the Church as His instrument) are mostly concerned with our eternal destiny, and everything in this life is about preparing for the next. We (I know especially I myself) can become overly concerned about fixing the problems of this life (paying bills, dealing with health issues, or the happiness of friends and family) and expecting God to at least help with this. God does sometimes help, even in spectacular, miraculous ways, but fixing the problem isn’t the main point of the miracles, or even of the problem. Everything in life, even the problems, are here to give us opportunities to love like God loves, which we need his grace to do. The vicissitudes of life can make it hard to remember what the real meaning of life is, and focusing on miracles, or the lack there of, can make that even harder still.
So while it’s certainly no coincidence that Saint Thomas in this portrait by Fra Angelico, and I both part our hair on the right, I don’t think there is some super deep reason for it. It might be truly miraculous, though, that you have read this far. I thank you that you did.