Never, never rest contented with any circle of ideas, but always be certain that a wider one is still possible.

The line urges intellectual restlessness: treat any settled “circle” of beliefs, tastes, or assumptions as provisional, because a larger horizon of understanding is always available. The repeated “Never, never” intensifies the warning against complacency and self-satisfaction, while the geometric metaphor suggests that ideas can expand outward without negating what came before—growth by enlargement rather than simple replacement. Read this way, the quote functions as a compact ethic of lifelong learning and curiosity, encouraging openness to new experiences, perspectives, and knowledge. It also implies humility: certainty should be tempered by the awareness that one’s current framework is partial and can be widened.