At the start of Tom Jones, we meet Squire Allworthy, a widower living with his unmarried sister Bridget on a fine estate called Paradise Hall in Somerset, in southwestern England. Squire Allworthy has a tragic past: not only did his beloved wife die some years before (after which he has decided never to remarry), but he has also lost his three children to illness. Poor dude.
When the novel starts, there is a big question mark floating over the plot: we've got this rich guy with no heirs. His inheritance could be a big opportunity for some young person out there. When Squire Allworthy returns home from a long business trip in London to find a baby sleeping in his bed, we have to ask: could this baby fill the gap in both Squire Allworthy's heart and in his last will and testament?
We know from the minute that Squire Allworthy decides to raise this baby that he's a good guy. After all, Squire Allworthy is willing to care for this kid as his own—he even gives the child his own first name, Thomas—even though he believes Tom to be the illegitimate child of Jenny Jones and the schoolmaster, Mr. Partridge. That's a huge responsibility for anybody to take on. But it's particularly serious for Squire Allworthy, since by raising this unknown child, he opens himself up to all kinds of nasty rumors that Tom must really be Squire Allworthy's bastard (which he isn't).
Squire Allworthy is the big man in his neighborhood: not only does he own a huge estate (Paradise Hall), but he is also a local judge and general authority figure for the villagers on his lands. So his willingness to foster Tom even though it is pretty bad for his reputation is a sign that he wants to do the right thing, in spite of what the local gossips may whisper about him behind his back.
Everything about Squire Allworthy's characterization emphasizes his positive traits: he's always offering good advice. His name is "Allworthy," or, worthy of all. He is generous with his money and does his best to help the poor and disadvantaged (like when he gives Mrs. Miller a London boarding-house that she can rent out to support herself and her daughters when her husband dies). The narrator even comes out and says that Squire Allworthy has "an agreeable person, a sound constitution, a solid understanding, and a benevolent heart" (1.2.1). In other words, he is good-looking, healthy, smart, and kind. What could be better?
(Actually, before we go any further, let's clear something up: a "squire" used to be a knight's assistant back in the olden days of jousts and medieval battles. But by the eighteenth century in England, "squire" was the official, inherited title for a country gentleman. To be honest, squires were pretty low down on the official totem pole of British titles and ranks. While being a squire was better than being a commoner, they weren't as important as full-on lords or ladies.)
Well, Squire Allworthy may be all-around awesome, but he isn't perfect. For a smart guy, he is surprisingly easy to fool. We can think of several examples off the top of our heads: there's his unfair conviction of Partridge for being Jenny Jones's baby daddy, based only on rumor and on the evidence of his insanely jealous wife. There is his decision to keep Misters Thwackum and Square on as tutors for Tom and Master Blifil, even though he knows that they are biased, foolish, and cruel men.
But of course, the biggest proof we have that Squire Allworthy isn't always a great judge of character is his treatment of Mr. Blifil. Squire Allworthy's faith in his nephew begins when he notices that Mr. Blifil's mom (Bridget, the squire's sister) just doesn't like her son that much:
When therefore [Squire Allworthy] plainly saw Master Blifil was absolutely detested (for that he was) by his own mother, he began […] to look with an eye of compassion upon him. (3.7.3)
So in a way, it's to Squire Allworthy's credit that he takes so strongly to Mr. Blifil, since he does it out of sympathy for a boy whose mother hates him. Yet, even if Squire Allworthy's motivations are good, his judgment is beyond terrible.
As it turns out, of course, Mr. Blifil is a low-down dirty deceiver. Mr. Blifil plays on Squire Allworthy's faith in him to manipulate his uncle into throwing Tom out of the house. He also tries to use Squire Allworthy to force Sophia into marriage against her will, something Squire Allworthy absolutely, totally condemns at the end of the novel.
Since Squire Allworthy always insists on seeing the best in people, he sometimes misses the glaring warning signs (like Mr. Blifil's hypocrisy and cruelty) that they don't deserve his trust. We have to say, we know he is supposed to be a good guy, but Squire Allworthy is annoyingly vulnerable to con men.