"All I contend for, is the utter impossibility, for some books, that you, or the most penetrating spirits upon earth, should know how this matter really stands" (1.18.12)
Despite how it seems, Tristram is going to keep his lips zipped. Writing allows readers to gain knowledge about events and character, but a good book has to gradually unveil itself, and Tristram, like a regular Agatha Christie, prides himself on keeping knowledge from even the cleverest reader.
"our minds shine not through the body, but are wrapt up here in a dark covering of uncrystallized flesh and blood; so that if we could come to the specific characters of them, we must go some other way to work" (1.23.4)
The truth about people isn't in their exterior but in the interiors, and in fact bodies just get in the way. This is kind of odd, because (thanks again, Facebook) it suggests that the best way to gain knowledge about people isn't actually to interact with them.
"the desire of knowledge, like the thirst of riches, increases ever with the acquisition of it" (2.3.3)
This statement makes knowledge seem like something that you can own and hoard, which suggests that after a certain point it's just superfluous. All the money in the world is great, but it just stops mattering after a while—we hear. (We sure wouldn't know from experience.) Someone like Walter Shandy, who hoards knowledge, can't actually use it in any meaningful way.
"stop!—go not one foot further into this thorny and bewildered track;--intricate are the steps! intricate are the mazes of this labyrinth! intricate are the troubles which the pursuit of this bewitching phantom KNOWLEDGE will bring upon thee." (2.3.8)
Knowledge is deceitful. It's great to have a little, but too much leads people on and eventually ends up confusing them. It seems like Tristram is suggesting it's better not to know too much—exactly the opposite stance taken by Sterne's contemporary, Alexander Pope: "A little learning is a dangerous thing/ Drink deep, or taste not the Pierian spring."
The advantage of prying and peeping continually into his master's plans, &c., exclusive and besides what he gained HOBBY-HORSICALLY, as a body servant, Non Hobby-Horsical per se,—had become no mean proficient in the science; and was thought, by the cook and chamber-maid, to know as much of the nature of strongholds as my uncle Toby himself. (2.5.8)
Spying: a time-honored way of gathering knowledge. We see characters spy a few times in the novel (particularly Mrs. Shandy), and here we learn than Trim has a super high security clearance. The problem is that knowledge you get from spying is, well, incomplete. The cook and the chamber-maid probably aren't the best judges of how much Trim knows about fortifications.
I should have added, nor are we angels, I wish we were,—but men clothed with bodies, and governed by our imaginations;—and what a junketing piece of work of it there is, betwixt these and our seven senses,
In the seventeenth century, John Locke insisted that the best way to learn about the world was through the senses. Not so, Tristram says, who would no doubt throw out all eyewitness testimony.
The difference between them was, that my uncle Toby drew his whole knowledge of projectils from Nicholas Tartaglia—My father spun his, every thread of it, out of his own brain,—or reeled and cross-twisted what all other spinners and spinsters had spun before him, that 'twas pretty near the same torture to him. (5.16.1)
If sensory info isn't working for you, you can pick up a book or just plop down in your armchair and philosophize. Yeah, that's working out well for Toby and Walter. Really, Tristram doesn't leave us with much of a feeling that there's any point in trying to learn anything.
"It is with Love as with Cuckoldom--the suffering party is at least the third, but generally the last in the house who knows any thing about the matter:
Even knowledge about love has to be found out from someone else—senses aren't good enough on their own, especially when it comes to figuring out if that guy in Calculus actually likes your or just wants to copy your homework.
A daughter of Eve, for such was Widow Wadman, and 'tis all the character I intend to give of her— —"That she was a perfect woman,"
Of all the unknowable things in Tristram Shandy, women are perhaps the most mysterious. There's no understanding them, and there's no characterizing them. They're just … women. (Maybe you should just talk to them like normal people, Tristram.)
My uncle Toby knew little of the world; and therefore when he felt he was in love with widow Wadman, he had no conception that the thing was any more to be made a mystery of" (8.27.1)
Toby's such an innocent that he doesn't even know he's supposed to make a big deal of being in love. He has no idea how to flirt—he just tells Mrs. Wadman he likes her and figures that's the end of it. If he were more knowledgeable, he'd probably just make a mess of it. Poor guy needs some lessons from the Pickup Artist.