In Barbara Kingsolver's novel "The Lacuna," the quote highlights the unity and collective identity of a group. The imagery of a thousand fishes moving as one symbolizes how individual entities can come together to form a cohesive whole. This concept emphasizes the beauty and strength found in collaboration and shared purpose, suggesting that cooperation leads to a more vibrant existence.

The phrase "one great, bright, brittle altogetherness" also implies fragility within this unity. While the school of fish thrives on togetherness, the use of "brittle" suggests that such harmony can be delicate and easily disrupted. Kingsolver's work invites readers to reflect on the complexities of community and the balance between individuality and collective existence.