Gordon Brown, weighing things up.
Photograph: PA
In the second instalment of Sean Clarke's blog on words, he tackles the weighty matter of pensions.

Perhaps ill-advisedly, I asked our personal finance expert what topical word I should write about this week. She suggested pensions. Bit involved with her work, I thought. Was there anything to say? Well, there's some interest in the idea that the underlying concept of "regular payments of money" should evolve in two quite different directions in English (to mean "retirement income") and French, Spanish and Italian (to mean "boarding house"). Some interest, I say, but that's about it.

Then it struck me that this was a chance to resolve something I'd often noticed and never got round to looking up - namely the similarity in the Romance languages between words about thinking and words about weighing. The starkest example is in the two Italian words peso, "a weight", and penso, "I think". Might these two both relate to "pension"?

I turn to Chambers Etymological Dictionary (of English) and find that "pensionem" - the word that informs both French and English pension - comes from pendere, which my Collins Latin dictionary tells me means both "to weigh" and "to pay" - from the obvious circumstance that the best way of paying someone in coin is to weigh the amount. But the third meaning given is where it gets interesting: "(fig.) to ponder, value". Hold that thought. For now, back to the CED to check out "pensive", being an English word clearly derived from penser. The CED tells me that French "penser" comes from "pensare, 'weigh', 'consider', a frequentative form from pendere 'weigh'." Aha.

("Frequentative form", by the way, is a slightly unhelpful term for semantic purposes. It describes a verb derived according to certain rules from another, whose difference in meaning from the first is not always predictable; we have various sorts of the same thing in English, not least phrasal verbs. One Friday soon we'll play 'why English phrasal verbs and Latin verbs with prepositional prefixes are basically the same thing'. It will be fun.)

Now, it's pure speculation, but you can see why people who habitually used the word for "weigh" also to mean "consider" might want to split it in two - pendere for weighing, pensare for thinking. In English we can do this easily with phrasal verbs: we can weigh the baby, weigh up the options and weigh out the gold.

What I began to find intriguing was just how widespread this crossover between words of weighing, words of valuing and words of thinking is. As we've seen, "weigh" can mean all three in English, and, to return to ponder, which was given as the third English translation of "pendere" - why, that obviously comes from the Latin pond-us/-eris, "a weight", which by a roundabout route also gives us the word "pound".

To get topical, and to oblige our friend on the Money desk, we might think of Mr Brown, "a pensive chancellor pondering the question of pensions, and ponderously weighing up the value of the pound", and use very few words that didn't in the mists of time have a meaning to do with weight.

Thus fired up, I inevitably set my mind to thinking of other words to see if the idea held up, and came up with "consider". Could it, I guessed, be from con-sedere, to sit down together, (perhaps to talk over a problem)? Plausible, but most likely wrong: the CED tells us that it is "probably" from sid-us/-eris, a star (as in sidereal) and refers to the practice of divination by looking at the stars.

So I was ready to exclude "consider" from this discussion, until I realised that it is a near-perfect example of the weight > value > thought process working in the opposite direction. A consideration in contemporary English is a payment, and considerable often simply means big.

Over to you, then, considerate reader. I'm conscious that all this discussion has been on English and the Romance languages. Do you more enlightened souls know if these weight-thought metaphors occur in other more glamorous languages? Please let us know.

And by the way, you'll notice that we've chosen a title for our blog from your many, many excellent entries. Sean Roe, please email us with your details at books.editor@guardianunlimited.co.uk and we'll send out your prize.