In each of these four books it is especially important to guard against losing sight, in the details which must necessarily be discussed, of the principal thought to which they belong, and the progress of the whole exposition.
Lau liburu horietako bakoitzean oso bereziki zaindu behar dugu geure burua pentsamendu nagusia begietatik ez galtzetik bere azterketak beharrezkoak dituen xehetasunak direla-eta, baina ezta aurkezpen osoaren aurrerakuntza ere.