“People on a design team must be as happy to be wrong as right. If their ideas hold up under strong (but fair) criticism, then great, they can proceed with confidence. If their ideas are rejected with good rationale, then they have learned something. A healthy team is made up of people who have the attitude that it is better to learn something new than to be right.” - Sketching User Experiences by Bill Buxton

Purchase Sketching User Experiences to read Bill’s holistic approach to design as well as an explanation of how to use sketching to your advantage as a designer.

“Designers need to be more than ambassadors, they need to be fully functioning and fully aware members of strategic decision-making teams in a company.” - Nathan Shedroff

Read Kate Rutter’s interview with Nathan Shedroff for more thoughts on the role of design in business.
Edit: Fixed article URL - sorry about that

“While each discipline on the product team has its role to play, it is the true teamwork and collaboration of a cohesive product team that makes great user experiences possible.” -Pabini Gabriel-Petit

Read Pabini’s article “Sharing Ownership of UX” on UXmatters for her thoughts on how the entire product team must work together when making product decisions.