What exactly is "purity of heart"?

[Fizzer]

I have wondered about "purity of heart", because Goku can ride Kinto'un while Bulma can't because she's sort of sexual and vain, and tells lies. Goku, though, does seem to kill a lot of people in Dragon Ball, and that wasn't always the only option. Having a "pure heart" must just mean being ignorant, not knowingly doing anything wrong, or just having a blank mind altogether.

[Storm101]

Am I the only one that dislikes the assertion that having sexual desires = not pure? Master Roshi is not pure since he physically harrasses women, but calling anybody that is sexual unpure just seems dumb.

[Majin Steve]

I think it all goes back to be enrooted in that depiction of virginity, you know - white, pure, a whole cherry, a flower, something rather than nothing.

It's an interesting point you raise.

[Fizzer]

I only mentioned that because DB itself seems to imply that sexual desires are impure, at multiple points.

[Legendary Saiya-Jin]

Am I the only one that dislikes the assertion that having sexual desires = not pure? Master Roshi is not pure since he physically harrasses women, but calling anybody that is sexual unpure just seems dumb.

Nope. Lots of people that prefer to ignore consequences from selfish sexual practices resent the moral implications of chastity and abstinence.

[shreddinghead]

Goku does occassionally seem selfish and/or inconsiderate but his heart is in the right place. Does he make mistakes? Well, yes everybody does but he is always driven by the disire to help out others when it comes right down to it.

Vegeta says he's "pure evil" when he reveals himself to be Super Saiyan, but I highly doubt he was considering he'd obviously had some sort of non-rape romp with Bulma that resulted in Trunks.

Wha? Are you making a bad joke or something?

[Piccolo Daimao]

I only mentioned that because DB itself seems to imply that sexual desires are impure, at multiple points.

Despite the fact that Gokuu is seen riding the Kinto'un after Gohan was born.

[Ketchup_Revenge]

I think it all goes back to be enrooted in that depiction of virginity, you know - white, pure, a whole cherry, a flower, something rather than nothing.

It's an interesting point you raise.

Something about "virginity" and "cherry" being used in the same sentence seems a bit ironic (or perverse) to me

Wha? Are you making a bad joke or something?

Obviously.
But not entirely. I highly doubt Bulma would keep a man around who raped her, and I don't think Vegeta would be so crude. He seemed as interested in sex as Goku was (which means he wasn't at all) which really suggests that there had to be something else going on between him and Bulma on some emotional level, however miniscule it might have been.

Despite the fact that Gokuu is seen riding the Kinto'un after Gohan was born.

I agree, but it could imply sex for the sake of sex. There's nothing that suggests that Goku and Chi Chi ever had sex outside their desire for procreation, or "love-making", which is sex that's more about emotion than simple carnal desire, or "getting off". Or based on Gohan's age at the begining of Dragon Ball Z, it's very possible that he was simply the result of the consummation of marriage between Goku and Chi Chi.
Goten's conception most likely happened in that nine day gap before the Cell Games. If I remember correctly, Karin says something about Goku perhaps "sensing his end was near" or something along those lines. This happens immediately after Goku and Gohan leave Karin Tower. This very well could've been some psychologial desire for Goku to leave another piece of himself with Chi Chi before he died. It would explain why he was so relaxed, and why he had no problem staying dead.