It’s not like anything to be a bat

...at least not if you ac­cept a cer­tain line of an­thropic ar­gu­ment.

Thomas Nagel fa­mously challenged the philo­soph­i­cal world to come to terms with qualia in his es­say “What is it Like to Be a Bat?”. Bats, with sen­sory sys­tems so com­pletely differ­ent from those of hu­mans, must have ex­otic bat qualia that we could never imag­ine. Even if we de­duce all the phys­i­cal prin­ci­ples be­hind echolo­ca­tion, even if we could spec­ify the move­ment of ev­ery atom in a bat’s senses and ner­vous sys­tem that rep­re­sents its knowl­edge of where an echolo­cated in­sect is, we still have no idea what it’s like to feel a sub­jec­tive echolo­ca­tion quale.

An­thropic rea­son­ing is the idea that you can rea­son con­di­tion­ing on your own ex­is­tence. For ex­am­ple, the Dooms­day Ar­gu­ment says that you would be more likely to ex­ist in the pre­sent day if the over­all num­ber of fu­ture hu­mans was medium-sized in­stead of hu­mon­gous, there­fore since you ex­ist in the pre­sent day, there must be only a medium-sized num­ber of fu­ture hu­mans, and the apoc­a­lypse must be nigh, for val­ues of nigh equal to “within a few hun­dred years or so”.

The Bud­dhists have a parable to mo­ti­vate young seek­ers af­ter en­light­en­ment. They say—there are zillions upon zillions of in­sects, trillions upon trillions of lesser an­i­mals, and only a rel­a­tive hand­ful of hu­man be­ings. For a rein­car­nat­ing soul to be born as a hu­man be­ing, then, is a rare and pre­cious gift, and an op­por­tu­nity that should be seized with great en­thu­si­asm, as it will be end­less eons be­fore it comes around again.

What­ever one thinks of rein­car­na­tion, the parable raises an in­ter­est­ing point. Con­sid­er­ing the vast num­ber of non-hu­man an­i­mals com­pared to hu­mans, the prob­a­bil­ity of be­ing a hu­man is van­ish­ingly low. There­fore, chances are that if I could be an an­i­mal, I would be. This makes a strong an­thropic ar­gu­ment that it is im­pos­si­ble for me to be an an­i­mal.

The phrase “for me to be an an­i­mal” may sound non­sen­si­cal, but “why am I me, rather than an an­i­mal?” is not ob­vi­ously sillier than “why am I me, rather than a per­son from the far fu­ture?”. If the dooms­day ar­gu­ment is suffi­cient to prove that some catas­tro­phe is pre­vent­ing me from be­ing one of a trillion space­far­ing cit­i­zens of the colonized galaxy, this ar­gu­ment hints that some­thing is pre­vent­ing me from be­ing one of a trillion bats or birds or in­sects.

And this could be that an­i­mals lack sub­jec­tive ex­pe­rience. This would ex­plain quite nicely why I’m not an an­i­mal: be­cause you can’t be an an­i­mal, any more than you can be a toaster. So Thomas Nagel can stop wor­ry­ing about what it’s like to be a bat, and the rest of us can eat veal and foie gras guilt-free.

But be­fore we break out the dolphin sausages—this is a pretty weird con­clu­sion. It sug­gests there’s a qual­i­ta­tive and dis­con­tin­u­ous differ­ence be­tween the ner­vous sys­tem of other be­ings and our own, not just in what ca­pac­i­ties they have but in the way they cause ex­pe­rience. It should make du­al­ists a lit­tle bit hap­pier and ma­te­ri­al­ists a lit­tle bit more con­fused (though it’s far from knock­out proof of ei­ther).

The most sig­nifi­cant ob­jec­tion I can think of is that it is sig­nifi­cant not that we are be­ings with ex­pe­riences, but that we know we are be­ings with ex­pe­riences and can self-iden­tify as con­scious—a dis­tinc­tion that ap­plies only to hu­mans and maybe to some species like apes and dolphins who are rare enough not to throw off the num­bers. But why can’t we use the refer­ence class of con­scious be­ings if we want to? One might as well con­sider it sig­nifi­cant only that we are be­ings who make an­thropic ar­gu­ments, and imag­ine there will be no Dooms­day but that an­thropic rea­son­ing will fall out of fa­vor in a few decades.

But I still don’t fully ac­cept this ar­gu­ment, and I’d be pretty happy if some­one could find a more sub­stan­tial flaw in it.