Final answer:
The theme that 'it's often better to do a good job on something simple than attempt too many things at once' is best represented by the quote 'Simplify, simplify. I say, let your affairs be as two or three, and not a hundred or a thousand;...' from Thoreau's 'Walden', and 'Better a diamond with a flaw than a pebble without.'
Step-by-step explanation:
To identify the quotation that best encapsulates the theme 'it's often better to do a good job on something simple than attempt too many things at once', we have to look for a phrase that reflects the virtues of simplicity and focused effort. The quotation that fits this theme is:
'Simplify, simplify. I say, let your affairs be as two or three, and not a hundred or a thousand;...'
This quote from Henry David Thoreau's 'Walden' encourages the reader to eschew complexity in favor of simplicity, highlighting the value of concentrating on a few important tasks rather than spreading oneself too thin. By focusing on a more manageable number of tasks, you are more likely to do them well. Similarly, the quotation:
'Better a diamond with a flaw than a pebble without.'
suggests that something modest done well is preferable to a multitude of things done poorly. Both quotations emphasize the importance of quality over quantity, which aligns with the student's theme. When using quotations in writing, they should be integrated smoothly to ensure minimal disruption and to support your argument.