One of the most common criticisms of cryonics is to argue that cryonics can only be a legitimate endeavor when there is (peer reviewed) demonstration of whole body suspended animation. Advocates of cryonics  point out that this is an unreasonable position because it sets a standard for rational decision making (certainty) that is rarely encountered, if ever, in real life. People make decisions under conditions of uncertainty all the time. Why should cryonics be held to higher standards?

Like many other arguments against cryonics, this line of criticism is addressed by Robert Ettinger in his book Man into Superman (1972):

There is one more foible of many scientists and physicians important enough for separate attention: the notion that we should spend our money on research, not on cryonic suspension. This is nonsense on its face, and on the record.

To begin with, as repeatedly emphasized, those now dying cannot wait for more research, but must be given the benefit of whatever chance current methods offer. Most of us, if we are in our right minds, have limited interest in abstract humanity or remote posterity; we are primarily concerned with those near us, and cannot forego their probable physical benefit and certain psychological benefit. But even on their own terms, those who complain that research should come first are wrong.

Cryonics does not divert money from research, but channels money into research, and it is the only likely source of such funds in large amounts. Those who speak of using the funds for research “instead” of cryonics are out of touch with reality: these are not the alternatives. This is scarcely even arguable; it is a matter of record. Cryobiology has always been ill-supported, and in recent years support seems actually to have dwindled, partly because of a cutback in NASA funds. And private efforts to raise research money have had very little success. In contrast, organizations growing directly out of the cryonics program have donated money to cryobiological research without the help of a single big name: these include the Cryonics Societies of America, the Harlan Lane Foundation, and the Bedford Foundation. The sums involved have so far been very modest, but they will grow with the Societies. Note, for example, that Professor James Bedford, not a very wealthy man, left $100,000 of his estate for research in cryobiology and related areas, because he was planning cryonic suspension for himself. Does it require much imagination to see how this research will fare when people are being frozen by the thousands or by the millions?

Robert Ettinger makes another important point. Cryonics does not compete with resources for cryobiology research. If anything, it makes more money available to engage in such research. What better incentive to fund research than your own life being at stake? It is not a coincidence that the field of vitrification of complex organs has received great support from cryonics advocates. This funding has culminated in the identification of the least toxic vitrification agent known in the peer reviewed cryobiology literature and the maintenance of long-term potentiation (LTP) in vitrified brain slices.

So the idea that money should be allocated to research instead of cryonics is nonsense indeed. People can have rational reasons for choosing cryonics before suspended animation has been perfected. And when they make cryonics arrangements they have a stronger incentive to contribute to research that will benefit the science and practice of human cryopreservation.