Second sight, in Scottish Gaelic an da shealladh, "the two sights," describes an involuntary faculty in Highland and Hebridean folk tradition by which certain people see visions, most often a shrouded figure, a funeral, or a double of a living person, that are later understood to have foretold a death or misfortune.
The tradition was already well established when the Aberfoyle minister Robert Kirk collected local testimony about it for his manuscript The Secret Commonwealth of Elves, Fauns and Fairies, completed around 1691, which treated second sight alongside fairy belief as part of a coherent Highland cosmology of unseen orders.
The belief drew the attention of Lowland and English visitors for centuries afterward; Samuel Johnson and James Boswell, touring the Hebrides in 1773, discussed second sight seriously with islanders and neither dismissed it outright nor endorsed it, treating the volume and consistency of local testimony as worth recording even without proof. The tradition persisted as a marker of Highland identity into the twentieth century, discussed in regional folklore collections and occasionally by early SPR researchers interested in British folk psi belief, but it never became a national or international claim the way spiritualist mediumship did, remaining rooted in its specific Highland and Hebridean cultural context.