In our era of email, do handwritten letters still matter? In this fascinating book, Simon Garfield makes a convincing case for why they do, being embodiments of intimate emotions that digital communications can't quite convey.

Goethe described letters as "the most beautiful, the most immediate breath of life"; Garfield elaborates that "letters have the power to grant us a larger life". He moves passionately through the ages, interweaving rigorous research with apposite examples. He applauds those letters that managed to achieve "the art of capturing a whole world on a single page", from Seneca, who revealed many of his philosophies in letter form, to those of Ted Hughes and Sylvia Plath and their "passion in ink".

The book is crammed with curiosities: rumour had it that Oscar Wilde would write a letter, affix a stamp and throw it out of his window, assuming a passerby would mail it.

This history of letters is also a study of reciprocity: do we get back what we put in? Not always; many letters do not receive a response and captured here is the particular pain of waiting to hear back once words have winged their way into the world. Three chapters are entitled "How to Write the Perfect Letter", but there is no perfect letter. There is no perfect book about letter writing, either, yet To the Letter thrills and engages most when it cuts to the core of human relationships, showing personalities pinned to the page in all their painful imperfections.

To the Letter is published by Canongate (£9.99). Click here to buy it for £7.99 with free UK p&p