Sympathy?

"Bah! it amounts to nothing, all this, if we only look at it in such
relations. For centuries have _stupides_ bothered their brains about
such matters, seeking to account for them. As well devote one's time to
puzzling over 'Aelia Laelia'! Mysteries were not meant to be put in
the spelling-books, Monsieur. Ah, bah! a far different path did
Cesar Prevost pursue! He studied these phenomena, not to _explain_
them,--being too wise to dream of living _par amours_ with such barren
virgins as are Whence and Why (your Bacon was very shrewd, Monsieur).
What cared I about _causes_? Let Descartes, and Polignac, and Reid, and
Cudworth, _et id omne genus_, famish themselves in this desert; but ask
it not of Cesar Prevost! He is always considerate to the impossible. He
says this, always:--Here we have certain interesting phenomena; their
causes are involved in mystery impenetrable; their esoteric nature is
beyond the reach of any microscope;--what then? My Heaven! let us do
what we _can_ with them. Let us seek out their _relations_; let us
investigate the laws regulating their interdependence,--if there be such
laws; and _apres_, let us inquire if there be any _practical results_
obtainable from such relations and laws.

"You follow me, Monsieur? _Eh, bien!_ This was the system, and Cesar
Prevost came speedily to _one_ law,--a law so important, that, like
Aaron's serpent, it put all the rest out of sight forever, engrossing
thereafter his whole attention. This law, which pervades the entire
animal economy, and is of course important in proportion to its
universality, is as follows:--_The sympathetic harmony between animals,
other things being equal, is _IN INVERSE PROPORTION _to their rank
in that scale of comparison in which man is taken as the maximum of
perfection._ Consequently, man is most deficient in this instinctive
something, which, for lack of a better term, I have ventured to style
'sympathetic harmony,' while the simplest organization has it most
developed. This last, you perceive, Monsieur, is only inductively
true;--when we get below a certain stage in the scale, we find the
difficulties of observation increase in a larger ratio than the
augmented sympathy, and so we are not compensated; 't is, for instance,
like the telescope, where, after you have reached a certain power, the
deficiency of light overbalances the degree of multiplication. Knowing
this, my first aim was to find out what animal would suit be