Richard Dawkins is also capable of undergoing startling transformations...
Religion makes specific claims about the universe which need to be substantiated, and need to be challenged – and if necessary, need to be ridiculed with contempt,” he told the cheering crowd on the National Mall.
“For example, if they say they're Catholic: Do you really believe, that when a priest blesses a wafer, it turns into the body of Christ? Are you seriously telling me you believe that? Are you seriously saying that wine turns into blood?”
If the answer is yes, Dawkins suggested atheists should show contempt for believers instead of ignoring the issue or feigning respect.
“Mock them,” he told the crowd. “Ridicule them! In public!” (Report on Reason Rally here.)
Sunday is the Feast of Corpus Christi, the Feast when Catholics celebrate the real presence of Christ in the transubstantiated elements of bread and wine. To put that in Dawkins speak, it's when us sky-fairy loons worship a meat biscuit.
So let's get the preliminaries out of the way. Yes, putting aside some nuances (it's not any old 'blessing' but 'consecration'), I believe that when the priest blesses a wafer and wine, they turn into the body and blood of Christ. Again, still on the preliminaries, the Church does not believe that, if you subject the (consecrated) host to chemical analysis etc, it will appear as flesh and blood: it's precisely to rule out such a view that the doctrine of transubstantiation exists. The accidents of the host are bread/wine; the substance of the host is flesh/blood. (It looks like bread, it smells like bread, but it's really flesh and blood.)
Now, it's one sort of irrationality if sky fairy worshippers went around claiming that (if you analyzed the host) it would turn out to be meat. It's another form of (alleged) irrationality if you claim that, despite all appearances, it really is meat. We hold the latter. We don't hold the former. Please get our irrationality right before mocking.
Given all that, what can I say to defend the rationality of transubstantiation? Firstly, let's get back to general principles. Catholicism contains faith and reason working hand in hand. Each will have a preponderance in different areas. Thus, in ethics, most Catholic doctrines are (I would argue) capable of being defended on the basis of unaided human reason. But every now and then, you will hit a doctrine which depends on faith: the trust that God (as wisdom) can see further and understand more than we can. Once that particular doctrine is accepted, you will find that it aids our understanding of the world. But to get into that position, you have to take it on trust.
Here's an analogy. No child is capable of rationally establishing the basis of arithmetic. But by taking arithmetic on trust, she will find herself introduced into and capable of operating in a more rationally comprehensible world. Similarly, no Catholic is able to prove the truth of transubstantiation beyond pointing to our (reasonable trust) in the specific words of God and in the Church's interpretation of those words. But if the doctrine is accepted, it enriches our understanding of the world.
OK. But how does this enrichment show itself? Here's a few suggestions:
a) It avoids a Christianity which suggests that God came to earth because we needed him to guide us, but then went away again. Christ never went away again: he remains constantly, really present in his Church.
b) Christianity, finally, is not about words or noise. It is about the silent, physical presence of God.
c) It emphasizes the Mass as sacrifice and links us into that Biblical and Classical tradition of sacrifice. Just as in the Jewish Temple, just as on pagan altars, we offer (real) flesh and blood.
d) It reminds us that earthly things can be transformed into heavenly things. Bread can be transformed into God. A human being could be God. I can become divinized and recover myself as the image of God. Matter is not evil.
e) 'There lives the dearest freshness deep down things' as Hopkins put it. There is a characteristic nightmare of transformation (typical in horror films) that, beneath the mask, lies a terrifying reality. Sartre puts it like this:
Transubstantiation resists the modern nightmare with the ancient truth: beneath appearances, there is depth and there is God.
Anyway, enough to give evidence of two points:
a) Catholics believe in transubstantiation not because they reason it is true, but because God (through the Bible and the Church) tell us it is true and we trust them. This is one of those moments when the trust earned on other occasions through rational proof asks us to go beyond -but not in contradiction to- reason. (Bit like with a child or spouse: every so often, you just have to trust them. But that trust has been earned.) But having believed it, it receives rational confirmation through the work it does.
b) Transubstantiation is not an idle doctrine: it does matter whether or not you believe it. I certainly wouldn't say that you can't be a Catholic without believing in transubstantiation: every Catholic is in some way a bad Catholic. But i) it's one thing to have personal problems with this or that doctrine: it's quite another to assert (or even teach) that it is wrong ('I don't understand' does not entail 'It is wrong'); ii) if you don't believe it, you are missing out on a fuller, richer understanding of the world.
And perhaps that's the final message. Catholic teachings fundamentally are not about a test of strength of will: there's no particular virtue in training yourself to believe 1001 different things before breakfast. They are, on the other hand, meant to be helpful: if you don't believe in them, or even entertain them as a possibility, you are missing out.